Buzzing sound from the LED backlight board
My 27 inch 2011 iMac started to buzz in the top left corner (when facing the screen). It was silent for the first 5 years I had it.
Then the buzz started. The buzz sound increases as I raise the brightness.
I changed the PSU. The buzz came back after 2 days. Then, I changed the LED backlight board and the buzz came back after an hour...
There is nothing left to change! If someone finds a fix, please let me know.
4条评论
Hows the houses AC power? Do you have a UPS or a surge suppressor?
You may want to check your buildings ground as well as your outlets something maybe leaking to it or the grounding rod is worn out.
由 Dan 完成的
@indydan just to clarify the Buzzing sound does come from the LED backlight board? the sound changes with the brightness?
由 oldturkey03 完成的
Dan. It has nothing to do with the AC power. Iam also an audiophile, so I have Oyaide receptacles and Shunyata gear for filtration distribution. Ok, so the Imac is plugged not into Shunyata gear, but a Monster power bar.
After more digging and an email exchange with the vendor who sold me the LED backlight board, it seems the problem is the logic board. the logic board is faulty, so it makes the power supply and LED backlight boards work too hard.
Bottom line is I have to change the logic board.
由 Daniel Hebert 完成的
Oldturkey. yes the sound comes from the LED backlight board. but the LED board is making the noise because of a faulty logic board.
The vendor who sold me the LED board said this was a problem with these iMacs, and that even the Apple store geniuses were not aware of the problem... He even offered to take back the LED board and refund me.
由 Daniel Hebert 完成的