Computer monitors are a prime example of hardware that should be serviced only by qualified technicians. The electricity that builds up inside these units can kill you, plain and simple. Furthermore, even unplugged, monitors pose a serious threat; it can take days for the electric charge to dissipate from within one.

Responses to a recent Technical Q&A posting clearly emphasize the dangers associated with monitors and the importance one should place on personal safety. Member AceViper described the following problem with his 19″ ViewSonic GS790 monitor:

  • The monitor makes a high-pitched noise, especially immediately after startup or after a resolution change.
  • Changing the refresh rate and/or resolution does not eliminate the sound. All refresh rates and resolutions have been tried.
  • Tilting the monitor up or down will stop the sound temporarily.
  • The sound is not always present.
  • The loudness fluctuates from day to day.
  • Changing the background color does affect the sound’s volume (lowers it), but the fix is only temporary.

AceViper writes, “I opened the monitor case to try and locate the sound. It seems to emanate from a black case in the back left corner of the monitor (facing the monitor [screen]). This box is the same box you adjust to change focus/brightness. I changed both the focus and the brightness, [but the changes] seemed to have no effect on the sound. [I’m] looking for a way to fix the problem so that it doesn’t come back, without having to buy a new monitor or get a refurbished one.”

Stay out of the box!
The first sentence “I opened the monitor case…” obviously touched a nerve with TechRepublic members. They were quick to warn AceViper about the seriousness of such action and gave the following advice.

From Still_learning, “Unless you are qualified to do monitor repairs, I would not venture inside a monitor case. You stand a good chance of a high-voltage static shock. As for the high pitch whine, this usually indicates a monitor that is on its way to equipment failure. I believe that a new or refurbished monitor is your best option, unless by chance, your monitor is still under warranty.”

Lee Paxton couldn’t agree more. “Don’t open up the monitor unless you are trained as an electronics engineer. Monitors have a very high amount of residual static electricity around the rear of the screen, and it has been known to stay there for days before discharging properly. One touch on that or some of the components on the board, and you’ll end up being thrown against the wall and possibly burned hands. (The voice of experience.)”

Luckily for AceViper, the monitor is still covered under the original manufacturer’s warranty. This is good news, but AceViper doesn’t really want to “send it in for repair (and be without a monitor for however long the repairs take) or end up with a refurbished replacement.” These are legitimate concerns. Obviously, a monitor is a computing requirement, and from the sound of it, AceViper needs his machine up and running. Second, no consumer wants a refurbished model after paying for a new one. Realistically though, he’s fortunate that the monitor is still under warranty. I say, let the professionals do their job; send it in for repairs.

Anna777 agrees, “Get it repaired with ViewSonic (while you still can) even if it means that they send you a refurbished one (which is most companies’ practice—after all, they are going to do the same with yours—fix it and send it to another customer with the same model under warranty). Your monitor is no longer new.”

The likely culprit
TheChas believes “loose windings on the flyback transformer (or some other parts in the horizontal circuit)” are the likely cause of the high-pitched sound. In his opinion, a knowledgeable monitor technician should be able to repair it by replacing the part or securing it with high-voltage-rated adhesive. He also reiterates Still_learning’s warning. “CAUTION: The parts that are most likely loose have [approximately] 40,000 volts on them. Any servicing needs to be done by a trained, qualified technician.”

Nmlhaus concurs, writing, “This is very common on all TVs and also large-screen monitors. The integrated high-voltage transformer (IHVT) has windings that are laminated in place under the black surface skin. Through age, heat, and vibration, the laminations deteriorate. What you get are 15KH noises that a lot of people…can’t even hear. The reason you hear it coming and going is that different brightness [settings] require different currents through the transformer, [which] causes the laminates to start singing. You need a new IHVT.”

So, what have we learned? Resist the urge to put your hands where they don’t belong. Poking around the inside of a monitor could cost you much more than the price of a replacement.