high pitched whine lcd monitors made in china

Hi. What you are experiencing is a form of coil whine. Try messing with the monitor settings in the included monitor on screen controls. You mentioned adjusting brightness on a previous monitor. Did you have any luck adjusting the brightness on this monitor?

It looks like your monitor has multiple inputs and an external power brick. I would try switching to a different hdmi port and moving the power brick as far away as possible. It may be your power brick that is emitting that harsh noise, and not the monitor itself. Try another power brisk. You can try listening to the power brick when unplugged from the monitor to see if it emitts that specific noise. This is not the most scientific test, as the brick is not under load when unplugged from the monitor, so it may not produce a coil whine at all. If it does, find a replacement / RMA from samsung.

I use this monitor at work. In the past week, I have noticed that when I turn my monitor on in the morning (usually 10am), I hear the high pitched whine noise. I always turn off my monitor after leaving work (around 7pm). I"ve repeated the same exact steps and it"s happened for a few days now.

After about 5 minutes, the noise becomes faint. I can still hear the whine if I listen closely. And after about 20 minutes, it goes away completely. We have 20 of the same monitors here at work and I have not heard the same problem from any of them.

I"m experiencing a very annoying high-pitched buzzing sound with my Studio Display, I"ve spoken to others on Twitter who also have the problem and I"ve had Apple support on the case but nothing was resolved.

I have an electric car with a charger built into the house power supply, when the car is plugged in and charging the Studio Display"s noise becomes excruciatingly high pitched and loud. Due to this I charge the car over night these days.

Here"s a video of the sound, it"s hard to pick up so you may need headphones. Ignore the background noise, the high pitched tone should be audible. In real life it"s much more obvious and very annoying.

I have a cheap LCD that sometimes exhibits this problem (Chimei CMV 938D). For me, the most effective solution is playing with the brightness levels - it never whines at 100% brightness. I"ve always assumed it was the capacitors, though I"ve never been sufficiently motivated to take it apart and investigate.

I"ve had this screen for 2 years now, and it"s done it since it was new, so while it might be an early warning of death, I"ve always just figured it was a function of a cheap build. Admittedly I don"t often run mine in the brightness range where it whines.

When the computer is on and the monitor"s display is turned off and it"s on standby (the green light is yellow), the monitor makes a high pitched noise (I don"t really know how to describe it) lasting about a second. It stops for a second and then repeats and follows that cycle. It is kind of annoying. I"ve never had a monitor do this before.

There are several discussions online about LCD monitor noise where high-pitched monitor noise was significantly reduced by using a combination of two settings. If I remember correctly, the gist of the solution was to use the the hardware-based (i.e. built into the monitor) settings to turn down the brightness and contrast, and then using the Windows-based or graphics card driver settings to turn up the corresponding setting.

However, when the monitor is on there is a slight buzz which doesn"t really bother me. I noticed it when doing the test described above because the buzz disappeared when the monitor was turned off and was replaced by the high pitched noise. Anyways, when I increased the brightness to 100 (max) the buzz went away just like you described.

Click to expand...Are you near a Wal-Mart or Target store. You can pickup a decent 18.5 LCD Widescreen Monitor for $85 and up when it"s on sale. Off sale $119 and up.

I"ve personally never heard this problem with computer LCDs monitors before - CRTs often, but not LCDs. That said, it has been a problem with larger big screen LCD TVs in the past so I suspect as users buy larger computer monitors, the problem may become more widespread - compounded by the fact folks sit 2 feet in front of computer displays. For the record - it is most likely transformers buzzing as they are notorious for it - and since many newer monitors, including this particular Dell, house the power supply internally, so too does the main power transformer sit only 2 feet away.

These LCD monitors can stop working all of a sudden then after a few months you want to try to turn it on back and bang! It works! In this user case there is a defective transformer or something with the power regulator. But dell won"t fix it they"ll just replace new or factory service.

Click to expand...Sounds like your into Green way of life.. I am like that I don"t pollute! But LCD and CRTs can destroy our environment. But DELL doesn"t like to repair anything just reuse what they have on stock. Just takes to much man hours to repair anything today. Gone is the 48 hour burn-in test. I"ve repaired a large number of DELL Latitudes with bad LCD screens and DELL CRT were the worst ones to own back in the day. Now that LCD screens are more in the norm not all goes through enough testing or quality control at DELL (China DELL).

samsung monitors do the same when on. the workaround to those affected and it will only affect those who have manually adjusted the contrast /brightness levels is to have the contrast at 0 and brightness at 100% if you wish to have a dimmer screen to work with. the problem only occurs when the brightness control is below 75%

Click to expand...it is not LCDs or CRTs, but ALL electronics that causes concerns. This is a concern because as I noted, and you repeated, it is cheaper to replace than to repair. That"s fine for our check books, just not for the environment, or future generations.

it is not LCDs or CRTs, but ALL electronics that causes concerns. This is a concern because as I noted, and you repeated, it is cheaper to replace than to repair. That"s fine for our check books, just not for the environment, or future generations.

Click to expand...Well I always try to repair/replace the LCD panels it can be done most of it just components need to be replace in 15 minutes. Some clients don"t want the added expense to do that. STill doesn"t really take that time to do. But all these systems are leased with DELL. DELL can either give you a factory serviced replacement (means they had tried to fix it) or a brand new one.

In fact LCD some HDTV that use LCD panel can create this effect with the buzzing. Not everyone going to hear this noise. On the LCD Monitor you"re run on top of that hardware. Turning up the brightness or down shouldn"t be the fix. That monitor has issues and needs to be fixed. Just don"t sit there with the problem.

There was a report on USA TV on 60 minutes on the dumping of all these electronic equipments (computers, CRTs, LCDs an etc) like where they end up. China is where. I know we have companies that come and collect old CRTs, LCDs and systems to either destroy or resale. They"re called ECO but who knows what happens when they leave our client sites?

In this case, I think it is important for LCD monitor users (whether with notebook monitors, or PC monitors) to know that backlight and inverter problems are not uncommon, and most importantly, can be repaired fairly easily by a competent repair person, and less expensively than replacing the whole monitor - or worse, the entire notebook. This too helps cut down on ewaste, which is being exported and dumped, not only in poor Chinese village landfills, but Indian and African landfills too.

In this case, I think it is important for LCD monitor users (whether with notebook monitors, or PC monitors) to know that backlight and inverter problems are not uncommon, and most importantly, can be repaired fairly easily by a competent repair person, and less expensively than replacing the whole monitor - or worse, the entire notebook. This too helps cut down on ewaste, which is being exported and dumped, not only in poor Chinese village landfills, but Indian and African landfills too.

The new monitor (with new cables as well) still unfortunately makes the buzz and whine noises but they aren"t quite as bad. No dead pixels that I can see either. But the screen does look a little different - a little bluer and darker/lighter in some places. I think that"s just because the viewing angle is really bad?

The new monitor (with new cables as well) still unfortunately makes the buzz and whine noises but they aren"t quite as bad. No dead pixels that I can see either. But the screen does look a little different - a little bluer and darker/lighter in some places. I think that"s just because the viewing angle is really bad?

Only a theory but many times proven over the years ... Some of your computer parts are made in part with coils (a copper wire wrapped around a core). Depending on the workload on the CPU / GPU, these coils sometime " whistle ", aka emit a high pitch sound.

The high pitched noise from many LCD monitors when their brightness is reduced can be utterly distracting. Here’s a simple workaround that can work quite well with most monitors for many users. Also, please participate in our Quiet / Noisy Monitor Survey!

Many computer users have run into the issue of whining LCD monitors. Usually, it does not occur when the monitor is set to full brightness, which is usually too bright for most users. The natural response is to turn the brightness down using the monitor’s controls. That’s when the monitor can start to emit some high frequency tones, which are described most often as buzzing or whining. The noise usually gets worse the more the screen is dimmed.

It can be piercing and annoying enough to overcome even relatively high ambient noise. If you’ve spent the time and effort to study the information on SPCR and managed to achieve super-quiet performance in your computer, this whine can be absolutely frustrating. In short, it can drive people crazy.

The source of the problem appears to be components in the electronic circuit which controls the brightness of the CFL bulb that lights most LCD monitors. Most likely, this is some form of PWM (pulse width modulation) circuit, a very useful tool that, alas, can have negative side effects. For example, while it allows a fan to start reliably at unusually low speed, an improperly matched PWM control circuit can cause a DC fan to emit more clicking, buzzing and chattering noise as it is slowed. A similar effect may be happening with the monitor CFL bulbs. To modify this electronic circuit in order to reduce or eliminate the whining noise is an impossible challenge for most users.

This workaround will obviously not work for LCD monitors that whine even at full brightness. A replacement with another sample or model is recommended in such cases. We have not tried replacing the CFL bulb of afflicted LCD monitors; it probably is not the cause, however. Interestingly, the whine of CRT monitors can usually be reduced by setting its internal brightness control down. It’s also not clear whether any LED-lit monitors suffer the same problem. CAUTION: If you are an image professional (or advanced amateur) who relies on color accuracy, this may not be a good solution. For details, please see the discussion in the forum linked below. If you find the color degradation with this approach to be serious, you may also want to try a combination of both monitor hardware brightness control and video driver software brightness reduction. With a decent monitor, for typical computer uage, you should be able to find a happy compromise between image integrity and aural peace.

Please help us help you! The SPCR staff and lab can only examine and report on a finite number of products. Reader contributions can expand our reach tremendously. Everyone viewing this page has a monitor. In the forum discussion linked above, please post the make and model of your monitor and whether it whines. If it does, describe the degree, nature and conditions. As this log grows, everyone can benefit by using it as a quick reference. When it gets big enough, we will turn it to a table with multiple models, samples and ratings, and keep it uptodate. It will become a highly useful resource for quiet monitor seekers.

We continue to explore the issue of high frequency tonal noise from many computer components. As we approach ever lower noise levels, this electronic whining often becomes critical; in “normal” (read: noisy) computers, it is masked by the noise of fans and hard drives. Power supplies, motherboards and video cards are the other main sources of electronic whine. The whine is often associated with power components, usually capacitors and coils. Poor circuit design is probably at fault; electronic resonances in circuits can cause the components to vibrate or ring, and the whining we hear is directly related to that ringing.

We have two appliances now that emit a very high pitched ringing when plugged into the 120vac. They are so high pitched that some in my family cannot hear them... but those who can it drives us nuts!

It is such a waste to only use the LCD for desktop computers. Connecting it up with a laptop PC has many merits for the user and can also bring out the latent power of the laptop.

A laptop can be put to more effective use if it is connected to an external LCD. The photograph shows an EIZO 23-inch wide-screen LCD connected by HDMI to a Sony VAIO C laptop (VPCCW28FJ/R).

This time we would like to suggest a style that can be used in both the home and the office, where a laptop and stand-alone LCD remain connected. A laptop already has an LCD, but using it with an additional stand-alone LCD offers various merits. Not only does it make the laptop environment more pleasant and convenient, it also expands the potential of the computer itself, for example by making it possible to use it for new purposes.

Even if the LCD is already connected to a desktop computer and being used for something other than the laptop, most monitors nowadays have two or more video inputs and they tend not to use this capability to the full. It is such a waste to let the laptop"s external display output function and the monitor"s video input function remain dormant, so we would like them to be put to effective use. Of course, we would also recommend the introduction of a new LCD to connect to your laptop.

The biggest merit of connecting a laptop with a stand-alone LCD is that it gives you a large screen and high resolution dual display environment. Standard laptop models usually come with a built-in 13-inch to 15-inch wide-screen LCD with a 1280 × 800 dot or 1366 × 768 dot resolution.

This level of resolution is good enough for basic Windows operations, but it goes without saying that a large, high-resolution computer screen is much more user-friendly. Combining a laptop with one of the latest wide-screen monitors enables you to easily construct a large-screen, high-resolution dual display environment. It is a real boon to dramatically boost the screen size and resolution while continuing to use your familiar laptop.

Another plus is that you can create the luxury of a "watching while" environment where you run the web browser, for instance, on the laptop"s built-in LCD and watch the video content on the large screen of the external monitor. This can be really useful for hobbies too. For example, while playing a game on the large external LCD screen you can check out strategies on websites, post information on a BBS or communicate with other users.

You can smoothly use multiple applications at the same time in the large workspace provided by a dual display. The photograph shows an EIZO 24.1-inch wide-screen LCD, the FlexScan SX2462W connected to a VAIO C. By supplementing the laptop"s built-in 1366 × 768 dot 14-inch wide-screen LCD with a 1920 × 1200 dot 24.1-inch wide-screen, it is possible to show more data at a time, a huge boost to work efficiency.

With two screens it"s easy to have full-screen display of the video content on one screen while you operate the computer on the other. The photograph shows an EIZO 23-inch wide-screen LCD monitor connected to a VAIO C. The VAIO C has HDMI output and the LCD monitor has HDMI input so visuals and sound can be transmitted by a single HDMI cable. The LCD monitor has full HD screen resolution (1920 × 1080 dot), making it the perfect match for HD video content.

At the office, it is very helpful for presentations to use "clone view" for the laptop"s built-in LCD and the external LCD screen. Clone view means showing exactly the same content on two display screens. It is normally set by a graphics driver function.

When holding small meetings it is certainly very convenient to be able to offer simple explanations of the presentation materials displayed on the external LCD, rather than having to ready a projector. Being able to explain about what is displayed on the screen means fewer documents to distribute, helping your office to "go paperless", which can only be a good thing.

Even if the upper limit is 1680 × 1050 dots, the LCD can still display the data if its own resolution is 1680 × 1050 dots or higher. In such cases, it is better to use a monitor that offers dot-by-dot display, which displays the input resolution as it is, or enlarged display, which maintains the screen"s aspect ratio as it is. You do not need to worry because EIZO wide-screen LCDs can handle such display methods (although in some cases they do not function properly depending on the laptop computer or input resolution).

This is an example of a low-resolution display on the 1920 × 1200 dot display SX2462W. Since dot-by-dot display outputs the physical "1 dot" of the LCD and the input resolution "1 dot" without enlargement or reduction, it is shown small in the center of the screen (photo on the left). The display is a little blurred if it is enlarged while maintaining the aspect ratio, but this method is suitable for displaying images as they are shown large with low resolution to make the most of the screen size (photo on the right). Many monitors that cannot handle such display methods enlarge the display to full screen regardless of the input resolution. In such cases you have to be careful as the aspect ratio of the image is altered (for example, people appear to be thinner or fatter).

It is easy to set up a dual display in Windows 7. A menu is displayed when you right-click on the desktop. From "Screen resolution" it is possible to detect and align the external LCD, and set details such as resolution, display method and which will be the main display screen.

The "Screen resolution" menu. If the external LCD is not automatically recognized, click on "Detect". After the monitor has been recognized, you can select the display mode from the "Multiple displays" drop-down menu. Select "Extend display screen" to make the laptop screen and the external LCD into a single display screen (dual display).

Select "Duplicate display screen" from the "Multiple displays" drop-down menu to display the same content on the laptop screen and the external LCD screen (clone view). With this drop-down menu you can also set it to display video on one of the LCDs.

It is also worth noting that Windows 7 has added functions so that dual display can be used more effectively. An active window can be moved to the screen of another LCD by simultaneously pushing "Windows" + "Shift" + "→" (or "←"). It is also possible to maximize the window by pressing "Windows" + "↑", minimize it by pressing "Windows" + "↓", and shift it to the left or right of each screen by pressing "Windows" + "→" (or "←"). Making good use of these shortcuts should enable the efficient placing of windows in the two screens.

We would recommend a wide-screen model with a screen resolution of 1920 × 1080 dots (Full HD) or 1920 × 1200 dots (WUXGA) as the LCD to connect to a laptop, so that you can make full use of the advantages of dual display. EIZO has an extensive line up of wide-screen LCDs which can offer many benefits, in addition to the merits of a large screen and high resolution, when used with a laptop for dual display.

With a 24.1 inch wide-screen like the SX2462W, an A3 sheet (two A4 sheets side by side) can be viewed in actual size, particularly effective for paper-based creative work ITmedia LCD Course II, Lesson 3: Which is better, 16:10 or 16:9 ? – "Screen size / resolution / aspect ratio"

We must not forget that EIZO"s wide-screen LCDs have non-glare screens (processed to reduce ambient light reflection). Nowadays the trend is for laptops to have an LCD with glare (glossy) surface treatment. While these can display images in bright color, reflected ambient light can sometimes be distracting.

A laptop screen is not so large and adjusting its angle can avoid the reflection of lights and so on, however it is not so easy with the large screen of an external LCD. When it comes to the large screen of an LCD in habitual use, a non-glare type that is not reflective is probably easier to see, as well as being kinder on the eyes. A large screen, high resolution and non-glare ensure that you can comfortably continue viewing over a prolonged period of time.

The surface treatment of an LCD makes a difference to the background reflection. Glare panels do not diffuse background light, making it easier to achieve high color purity, but easily reflect the user or lights (photo on the left). If the lights are similarly trained on a non-glare panel they do not have much effect, only appearing as a fuzzy brightness (photo on the right).

Another distinctive feature of EIZO wide-screen LCDs is a commitment to energy saving. They incorporate various power saving features that support "EcoView". A pivotal feature is the "EcoView Sense" adopted in the FlexScan EV series, such as the EV2333W.

This is the motion sensor on the front of the LCD. It constantly monitors the user"s movements to automatically take finely-tuned power saving measures. To be more precise, if the user"s presence is not detected for a specified period of time, for example if he leaves his seat, the monitor automatically switches to power save mode, and then automatically switches back when the user"s presence is detected again.

Other features include "Auto EcoView", which automatically optimizes the brightness of the LCD based on ambient lighting, and "EcoView Index", which displays a meter on the screen showing how much power is being saved. All these features can be expected to have a strong energy saving effect and to boost the user"s awareness of power saving, making them particularly useful in the office.

A standard laptop computer switches to sleep mode if the built-in LCD is closed while it is running but, if this function is turned off, a laptop can be treated as a "small desktop computer."

It can be set to use only the connected external LCD and not to react when the laptop"s built-in LCD is closed. The transformation into a small desktop PC is complete if you add a keyboard and mouse connected to the laptop via USB ports, for example. The OS is still running even though the laptop"s built-in LCD is closed, so you can carry out normal operations using the external keyboard and mouse, and also use the laptop"s built-in optical drives.

The idea is to use a large screen, high resolution external LCD at home or in the office, and to use the laptop"s built-in LCD as usual for mobile purposes. This helps to boost the longevity of the laptop"s built-in LCD and many people do use their laptop in this way. If you feel reluctant to use a dual display environment, where the screen is split in two, why not give this a try?

Select "Only show the desktop on 2" from the "Multiple displays" list in the "Screen resolution" menu. The laptop"s built-in LCD will be switched off and the external LCD will become the main display.

By making this simple setting your laptop can be used as a space saving desktop computer. Another plus is that the laptop"s built-in LCD will last longer.

Recently some high-end laptop computers, such as the Sony VAIO F, are insisting on good display quality for their LCDs. However, a typical laptop"s built-in LCD does not have as good image quality as a stand-alone LCD. This is only natural since the costs allowed for display quality are completely different for an LCD incorporated into the PC as one of its parts and a specialized LCD.

However, by using an EIZO wide-screen LCD a laptop user can still fully enjoy such benefits of a stand-alone high-quality LCD as excellent color reproduction, a wide viewing angle, more even display and a wealth of items that can be adjusted to improve image quality. This is a crucial point for people who use their computer for photographs and videos in particular.

EIZO"s wide-screen LCDs emphasize color reproduction, and the coloration in sRGB mode has a high degree of accuracy. The standard color gamut used in PC environments and Internet content is sRGB, so you need have no worries about viewing or editing videos and photographs. They can also display images on web pages, such as products in online shops or goods for sale in online auctions, in colors that are very close to the real thing. (This is also influenced by how the seller took the photographs and processed the images, so we cannot say that the colors will always be accurate.)

Furthermore, in addition to sRGB color gamut accuracy, the high resolution-oriented FlexScan SX has the added benefit of covering more than 95% of Adobe RGB. Adobe RGB is a color gamut whose definitions encompass more highly-saturated colors than sRGB. In other words, it can represent a larger number of colors and brighter hues than sRGB.

Adobe RGB is the de facto standard in the publishing field and, closer to home, is used in digital SLR cameras and high grade compact digital cameras. The FlexScan SX series can reproduce the colors of photos taken in Adobe RGB mode with almost perfect accuracy on the screen. Retouching photographs proceeds more efficiently since subtle differences in color can be checked on the screen.

An example of sRGB color gamut image data displayed on a standard laptop and on the SX2462W. The SX2462W"s reproducibility of sRGB mode is of a considerably high standard but the color balance on the laptop has been lost. This would make it difficult to perform rigorous photo retouching.

In this case, if the image is edited on the external LCD with its high color reproducibility and the many tool palettes in the application are grouped in the laptop"s built-in LCD, there is less need to display or hide the tool palettes or to switch back and forth, and the image data to be edited can be displayed in a large form, making for more efficient work.

In this case, if the image is edited on the external LCD with its high color reproducibility and the many tool palettes in the application are grouped in the laptop"s built-in LCD, there is less need to display or hide the tool palettes or to switch back and forth, and the image data to be edited can be displayed in a large form, making for more efficient work.

When doing things like photo retouching, using software where there is a lot of switching between tool palettes it is very handy to display the image data to be edited on the external LCD with its high color reproducibility, and to gather the palette tools to be used on the laptop"s built-in LCD.

Going back to the subject of laptop computers, it is not going too far to say that applications and functions are being spoiled in laptops whose built-in LCD"s image quality is not too good. Connecting a laptop to a monitor with high image quality dispels any concerns about work that deals with colors and also helps to bring out the laptop"s potential.

Combining an EIZO wide-screen LCD with a laptop computer makes viewing videos and images even more fun. Just being able to see them on a large screen is a pleasure, but what makes it even better is that our LCDs are equipped with Fine Contrast, the optimum image quality mode for video and visuals. You can also use the Custom mode to create the image quality you prefer.

We expect that you now understand how displaying screens from a laptop computer on a stand-alone LCD can create a very pleasant environment. It feels as if your everyday laptop has been transformed into a completely different desktop machine. Even if you only use laptop computers, it is definitely worthwhile to add a stand-alone LCD.

When choosing the type of LCD the most important consideration is to choose one with overall high quality. When it comes to that, we can recommend EIZO wide-screen LCDs to a broad range of laptop users. In addition to their high image quality, EIZO wide-screen LCD are built with careful attention to detail, including non-glare screens, versatile stand features, dot-by-dot capability, abundant image quality modes, and our proprietary eco-functions. We want you to make full use of your beloved laptop computer along with an EIZO wide-screen LCD.

This time we have spoken about how an external LCD can be connected to a laptop computer, but if your main machine is a desktop computer then you probably already have a LCD.

In which case, why not consider adding a full HD (1920 × 1080 dot) or WUXGA (1920 × 1200 dot) wide-screen LCD and creating a more advanced dual display environment to further enhance your computer"s usability.

The dual display environment of a desktop PC has a wider range of options than a laptop computer, which is already installed with an LCD. Depending on the combination of products used you can seek for a larger screen, higher resolution and better image quality.

The photograph below shows two EIZO 24.1-inch WUXGA (1920 × 1200 dot) models being used side by side for an overwhelming super high resolution of 3840 × 1200 dots in total.

You can get a super high resolution of 3840 × 1200 dots in total by putting two 24.1-inch 1920 × 1200 dot wide-screen LCDs side by side. The advantage in this is that a larger screen and higher resolution are achieved at a lower cost than buying a single 30-inch high resolution model

In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference.magnetic deflection, using a deflection yoke. Electrostatic deflection is commonly used in oscilloscopes.

A CRT is a glass envelope which is deep (i.e., long from front screen face to rear end), heavy, and fragile. The interior is evacuated to 0.01 pascals (1×10−7 atm)×10−12 atm) or less,implosion that can hurl glass at great velocity. The face is typically made of thick lead glass or special barium-strontium glass to be shatter-resistant and to block most X-ray emissions. CRTs make up most of the weight of CRT TVs and computer monitors.

Since the mid-late 2000"s, CRTs have been superseded by flat-panel display technologies such as LCD, plasma display, and OLED displays which are cheaper to manufacture and run, as well as significantly lighter and less bulky. Flat-panel displays can also be made in very large sizes whereas 40 in (100 cm) to 45 in (110 cm)

In 1987, flat-screen CRTs were developed by Zenith for computer monitors, reducing reflections and helping increase image contrast and brightness.float glass.

In the mid-2000s, Canon and Sony presented the surface-conduction electron-emitter display and field-emission displays, respectively. They both were flat-panel displays that had one (SED) or several (FED) electron emitters per subpixel in place of electron guns. The electron emitters were placed on a sheet of glass and the electrons were accelerated to a nearby sheet of glass with phosphors using an anode voltage. The electrons were not focused, making each subpixel essentially a flood beam CRT. They were never put into mass production as LCD technology was significantly cheaper, eliminating the market for such displays.

Beginning in the late 90s to the early 2000s, CRTs began to be replaced with LCDs, starting first with computer monitors smaller than 15 inches in size,Hitachi in 2001,Flat-panel displays dropped in price and started significantly displacing cathode-ray tubes in the 2000s. LCD monitor sales began exceeding those of CRTs in 2003–2004

Despite being a mainstay of display technology for decades, CRT-based computer monitors and televisions are now virtually a dead technology. Demand for CRT screens dropped in the late 2000s.

The outer conductive coating is connected to ground while the inner conductive coating is connected using the anode button/cap through a series of capacitors and diodes (a Cockcroft–Walton generator) to the high voltage flyback transformer; the inner coating is the anode of the CRT,voltage multiplier for the current delivered by the flyback.

The anode cap connection in modern CRTs must be able to handle up to 55–60 kV depending on the size and brightness of the CRT. Higher voltages allow for larger CRTs, higher image brightness, or a tradeoff between the two.corona discharge.

The flyback transformer is also known as an IHVT (Integrated High Voltage Transformer) if it includes a voltage multiplier. The flyback uses a ceramic or powdered iron core to enable efficient operation at high frequencies. The flyback contains one primary and many secondary windings that provide several different voltages. The main secondary winding supplies the voltage multiplier with voltage pulses to ultimately supply the CRT with the high anode voltage it uses, while the remaining windings supply the CRT"s filament voltage, keying pulses, focus voltage and voltages derived from the scan raster. When the transformer is turned off, the flyback"s magnetic field quickly collapses which induces high voltage in its windings. The speed at which the magnetic field collapses determines the voltage that is induced, so the voltage increases alongside its speed. A capacitor (Retrace Timing Capacitor) or series of capacitors (to provide redundancy) is used to slow the collapse of the magnetic field.

The design of the high voltage power supply in a product using a CRT has an influence in the amount of x-rays emitted by the CRT. The amount of emitted x-rays increases with both higher voltages and currents. If the product such as a TV set uses an unregulated high voltage power supply, meaning that anode and focus voltage go down with increasing electron current when displaying a bright image, the amount of emitted x-rays is as its highest when the CRT is displaying a moderately bright images, since when displaying dark or bright images, the higher anode voltage counteracts the lower electron beam current and vice versa respectively. The high voltage regulator and rectifier vacuum tubes in some old CRT TV sets may also emit x-rays.

However, electrostatic focusing cannot be accomplished near the final anode of the CRT due to its high voltage in the dozens of Kilovolts, so a high voltage (≈600

During retracing of the electron beam, the preamplifier that feeds the video amplifier is disabled and the video amplifier is biased to a voltage higher than the cutoff voltage to prevent retrace lines from showing, or G1 can have a large negative voltage applied to it to prevent electrons from getting out of the cathode.Vertical blanking interval and Horizontal blanking interval.) Incorrect biasing can lead to visible retrace lines on one or more colors, creating retrace lines that are tinted or white (for example, tinted red if the red color is affected, tinted magenta if the red and blue colors are affected, and white if all colors are affected).

There are two types of deflection: magnetic and electrostatic. Magnetic is usually used in TVs and monitors as it allows for higher deflection angles (and hence shallower CRTs) and deflection power (which allows for higher electron beam current and hence brighter images)

The deflection coils are driven by sawtooth signalsHorizontal scan rate) of 15 to 240 kHz depending on the refresh rate of the CRT and the number of horizontal lines to be drawn (the vertical resolution of the CRT). The higher frequency makes it more susceptible to interference, so an automatic frequency control (AFC) circuit may be used to lock the phase of the horizontal deflection signal to that of a sync signal, to prevent the image from becoming distorted diagonally. The vertical frequency varies according to the refresh rate of the CRT. So a CRT with a 60 Hz refresh rate has a vertical deflection circuit running at 60 Hz. The horizontal and vertical deflection signals may be generated using two circuits that work differently; the horizontal deflection signal may be generated using a voltage controlled oscillator (VCO) while the vertical signal may be generated using a triggered relaxation oscillator. In many TVs, the frequencies at which the deflection coils run is in part determined by the inductance value of the coils.

Due to the high frequency at which the horizontal deflection coils operate, the energy in the deflection coils must be recycled to reduce heat dissipation. Recycling is done by transferring the energy in the deflection coils" magnetic field to a set of capacitors.

Mostly used in oscilloscopes. Deflection is carried out by applying a voltage across two pairs of plates, one for horizontal, and the other for vertical deflection. The electron beam is steered by varying the voltage difference across plates in a pair; For example, applying a voltage to the upper plate of the vertical deflection pair, while keeping the voltage in the bottom plate at 0 volts, will cause the electron beam to be deflected towards the upper part of the screen; increasing the voltage in the upper plate while keeping the bottom plate at 0 will cause the electron beam to be deflected to a higher point in the screen (will cause the beam to be deflected at a higher deflection angle). The same applies with the horizontal deflection plates. Increasing the length and proximity between plates in a pair can also increase the deflection angle.

SMPTE-C phosphors have properties defined by the SMPTE-C standard, which defines a color space of the same name. The standard prioritizes accurate color reproduction, which was made difficult by the different phosphors and color spaces used in the NTSC and PAL color systems. PAL TV sets have subjectively better color reproduction due to the use of saturated green phosphors, which have relatively long decay times that are tolerated in PAL since there is more time in PAL for phosphors to decay, due to its lower framerate. SMPTE-C phosphors were used in professional video monitors.

Variations in anode voltage can lead to variations in brightness in parts or all of the image, in addition to blooming, shrinkage or the image getting zoomed in or out. Lower voltages lead to blooming and zooming in, while higher voltages do the opposite.

Doming is a phenomenon found on some CRT televisions in which parts of the shadow mask become heated. In televisions that exhibit this behavior, it tends to occur in high-contrast scenes in which there is a largely dark scene with one or more localized bright spots. As the electron beam hits the shadow mask in these areas it heats unevenly. The shadow mask warps due to the heat differences, which causes the electron gun to hit the wrong colored phosphors and incorrect colors to be displayed in the affected area.

Size is limited by anode voltage, as it would require a higher dielectric strength to prevent arcing (corona discharge) and the electrical losses and ozone generation it causes, without sacrificing image brightness. The weight of the CRT, which originates from the thick glass needed to safely sustain a vacuum, imposes a practical limit on the size of a CRT.

At high deflection angles, resolutions and refresh rates (since higher resolutions and refresh rates require significantly higher frequencies to be applied to the horizontal deflection coils), the deflection yoke starts to produce large amounts of heat, due to the need to move the electron beam at a higher angle, which in turn requires exponentially larger amounts of power. As an example, to increase the deflection angle from 90 to 120°, power consumption of the yoke must also go up from 40 watts to 80 watts, and to increase it further from 120 to 150°, deflection power must again go up from 80 watts to 160 watts. This normally makes CRTs that go beyond certain deflection angles, resolutions and refresh rates impractical, since the coils would generate too much heat due to resistance caused by the skin effect, surface and eddy current losses, and/or possibly causing the glass underneath the coil to become conductive (as the electrical conductivity of glass decreases with increasing temperature). Some deflection yokes are designed to dissipate the heat that comes from their operation.

On CRTs, refresh rate depends on resolution, both of which are ultimately limited by the maximum horizontal scanning frequency of the CRT. Motion blur also depends on the decay time of the phosphors. Phosphors that decay too slowly for a given refresh rate may cause smearing or motion blur on the image. In practice, CRTs are limited to a refresh rate of 160 Hz.quantum dot LCDs (QLEDs) are available in high refresh rates (up to 144 Hz)

CRT monitors can still outperform LCD and OLED monitors in input lag, as there is no signal processing between the CRT and the display connector of the monitor, since CRT monitors often use VGA which provides an analog signal that can be fed to a CRT directly. Video cards designed for use with CRTs may have a RAMDAC to generate the analog signals needed by the CRT.multisyncing.

The convergence signal may instead be a sawtooth signal with a slight sine wave appearance, the sine wave part is created using a capacitor in series with each deflection coil. In this case, the convergence signal is used to drive the deflection coils. The sine wave part of the signal causes the electron beam to move more slowly near the edges of the screen. The capacitors used to create the convergence signal are known as the s-capacitors. This type of convergence is necessary due to the high deflection angles and flat screens of many CRT computer monitors. The value of the s-capacitors must be chosen based on the scan rate of the CRT, so multi-syncing monitors must have different sets of s-capacitors, one for each refresh rate.

Color CRT displays in television sets and computer monitors often have a built-in degaussing (demagnetizing) coil mounted around the perimeter of the CRT face. Upon power-up of the CRT display, the degaussing circuit produces a brief, alternating current through the coil which fades to zero over a few seconds, producing a decaying alternating magnetic field from the coil. This degaussing field is strong enough to remove shadow mask magnetization in most cases, maintaining color purity.deform (bend) the shadow mask, causing a permanent color distortion on the display which looks very similar to a magnetization effect.

Beam-index tubes, also known as Uniray, Apple CRT or Indextron,Philco to create a color CRT without a shadow mask, eliminating convergence and purity problems, and allowing for shallower CRTs with higher deflection angles.

In some vacuum tube radio sets, a "Magic Eye" or "Tuning Eye" tube was provided to assist in tuning the receiver. Tuning would be adjusted until the width of a radial shadow was minimized. This was used instead of a more expensive electromechanical meter, which later came to be used on higher-end tuners when transistor sets lacked the high voltage required to drive the device.

Some displays for early computers (those that needed to display more text than was practical using vectors, or that required high speed for photographic output) used Charactron CRTs. These incorporate a perforated metal character mask (stencil), which shapes a wide electron beam to form a character on the screen. The system selects a character on the mask using one set of deflection circuits, but that causes the extruded beam to be aimed off-axis, so a second set of deflection plates has to re-aim the beam so it is headed toward the center of the screen. A third set of plates places the character wherever required. The beam is unblanked (turned on) briefly to draw the character at that position. Graphics could be drawn by selecting the position on the mask corresponding to the code for a space (in practice, they were simply not drawn), which had a small round hole in the center; this effectively disabled the character mask, and the system reverted to regular vector behavior. Charactrons had exceptionally long necks, because of the need for three deflection systems.

CRTs can emit a small amount of X-ray radiation; this is a result of the electron beam"s bombardment of the shadow mask/aperture grille and phosphors, which produces bremsstrahlung (braking radiation) as the high-energy electrons are decelerated. The amount of radiation escaping the front of the monitor is widely considered not to be harmful. The Food and Drug Administration regulations in milliroentgens per hour at a distance of 5 cm (2 in) from any external surface; since 2007, most CRTs have emissions that fall well below this limit.rem.millirem. For comparison, the average background radiation in the United States is 310 millirem a year. Negative effects of chronic radiation are not generally noticeable until doses over 20,000 millirem.

At low refresh rates (60 Hz and below), the periodic scanning of the display may produce a flicker that some people perceive more easily than others, especially when viewed with peripheral vision. Flicker is commonly associated with CRT as most televisions run at 50 Hz (PAL) or 60 Hz (NTSC), although there are some 100 Hz PAL televisions that are flicker-free. Typically only low-end monitors run at such low frequencies, with most computer monitors supporting at least 75 Hz and high-end monitors capable of 100 Hz or more to eliminate any perception of flicker.sonar or radar may have long persistence phosphor and are thus flicker free. If the persistence is too long on a video display, moving images will be blurred.

50 Hz/60 Hz CRTs used for television operate with horizontal scanning frequencies of 15,750 and 15,734.25 Hz (for NTSC systems) or 15,625 Hz (for PAL systems).human hearing and are inaudible to many people; however, some people (especially children) will perceive a high-pitched tone near an operating CRT television.magnetostriction in the magnetic core and periodic movement of windings of the flyback transformer

This problem does not occur on 100/120 Hz TVs and on non-CGA (Color Graphics Adapter) computer displays, because they use much higher horizontal scanning frequencies that produce sound which is inaudible to humans (22 kHz to over 100 kHz).

High vacuum inside glass-walled cathode-ray tubes permits electron beams to fly freely—without colliding into molecules of air or other gas. If the glass is damaged, atmospheric pressure can collapse the vacuum tube into dangerous fragments which accelerate inward and then spray at high speed in all directions. Although modern cathode-ray tubes used in televisions and computer displays have epoxy-bonded face-plates or other measures to prevent shattering of the envelope, CRTs must be handled carefully to avoid personal injury.

Due to the toxins contained in CRT monitors the United States Environmental Protection Agency created rules (in October 2001) stating that CRTs must be brought to special e-waste recycling facilities. In November 2002, the EPA began fining companies that disposed of CRTs through landfills or incineration. Regulatory agencies, local and statewide, monitor the disposal of CRTs and other computer equipment.

As electronic waste, CRTs are considered one of the hardest types to recycle.phosphors, both of which are necessary for the display. There are several companies in the United States that charge a small fee to collect CRTs, then subsidize their labor by selling the harvested copper, wire, and printed circuit boards. The United States Environmental Protection Agency (EPA) includes discarded CRT monitors in its category of "hazardous household waste"

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Why MkII?Since their release, word has spread on the quality and value found in the original JBL 3 Series, resulting in wide adoption from hobbyists to high-end professionals working in music, film, post, and broadcast production worldwide. With such an obvious hit, you might ask, "Why update now?" On every project at JBL, there’s always a handful of features or improvements that the engineering team can’t squeeze in before going to production. 3 Series was no different. When the opportunity presented itself, we decided to make those final improvements to the transducers, add a frequently-requested feature, and apply the latest manufacturing learnings. The result—a new edition of this popular studio monitor that retains the best qualities of the original, but now looks better, sounds better, and provides transparent sound in even more production environments.

Patented Image Control WaveguideReveal impressive detail, ambience and depth in your mixes thanks to the groundbreaking JBL Image Control Waveguide. Originally developed for JBL’s flagship M2 Master Reference Monitor, this patented innovation ensures an acoustically seamless transition between the low- and high-frequency transducers and provides an immersive soundstage with precise imaging. Offering a broad sweet spot and neutral frequency response, JBL 305P MkII delivers a crystal-clear representation of your mix—revealing subtle details, even when listening off-axis.

Your Mix is Only as Good as Your MonitorsTo help you make the best mix decisions, JBL equipped the 305P MkII with acclaimed 3 Series transducers that now perform even better. Hear deep, accurate and tightly controlled bass thanks to a long-throw 5" woofer and the patented JBL Slip Stream™ low-frequency port. Enjoy soaring, immaculately detailed highs via the woven-composite 1" Neodymium tweeter. JBL engineers took things to the next level with faster HF transient response through fine-tuned ferrofluid damping, and greater low frequency linearity and lower harmonic distortion courtesy of an enhanced woofer design. The result is a studio monitor you can trust—with unmatched peak handling, stunning dynamics and neutral frequency response that’s unbeatable in its class.

Tailored Sound to Fit Your StudioThe dimensions and acoustics of a room can have a major effect on sonic accuracy, and that’s why JBL 305P MkII lets you adjust the response to fit your studio. The new Boundary EQ attenuates the low-end boost that can occur when you place monitors directly on the desktop or near walls. The 3-position HF Trim switch allows you to adjust the high-frequency response of the 305P MkII to tailor it to room acoustics or personal tastes.

JBL Professional ReliabilityJBL Professional studio monitors are designed for reliable performance, even when projects push your gear to the limit. Before being approved for production, 3 Series monitors must first pass JBL’s strenuous Power Test. Each model is required to perform flawlessly at maximum volume for an unheard-of 100 hours—without failure. As a result, you can depend on 305P MkII monitors to deliver consistently excellent sound reproduction for years to come.

I"m getting a soft high pitched whine coming out of my speakers, while my computer is active. It"s a B, 2 octaves above middle C, and it"s a sawtooth wave.

I"m using Studio Controls, which configures a pulse_out which can be configured to to run pulseaudio through Jack. I have to manually configure that output of Pulseaudio to jack in QJackCtrl each time I start up the OS, so when the computer starts, Jack controls the audio outs. However, the whine begins BEFORE I do this pulse configuration -- even though no other system sounds are audible. So my whine seems to be coming from Jack.

Right from the beginning the power supply (and a replacement power supply the sent me after I complained) made an easily audible (when not listening to music or the like of course) high pitch sound. This is when it is just lying behind my desk on the floor.

All power supplies of this type makes buzzing sounds if you put it right against your ear (power supplies for laptops, speakers, monitors etc), so that"s not what I am talking about.

It is the kind of sound whose intensity changes dramatically with the angle of your head. Change the angle of your head the tiniest bit and you cannot hear it. Change it back and it is unmistakably there again. It makes me the most irritated in the morning when I wake up (my bed and the speakers are in the same room, I"m a student, living in a small apartment). No other noises are there, your ears/brain have had all night to "reset" and then there is this high pitch sound if you place your head in the wrong angle on the pillow.

Normally, the faster the drive motor spins, the higher-pitched the resulting sound will be, and there is a greater chance of a low hum. Hard drives are generally audible, especially 3.5". Perhaps: Historically, drives have made an acceptable amount of perceptible noise. However, there can be exceptions even during normal use.

Enterprise class HDDs are designed to provide higher performance and reliability. However, this elevated performance can include increased levels of noise versus standard drives.

Different use cases may cause different levels of sound. For example, writing new data to an encrypted volume may produce a higher level of noise compared to a standard volume.