Chosen Solution
Hi. A friend have a problem with his 27" Thunderbolt display. Is it really annoying buzzing sound. My first guess would be the power supply?? The display in functioning OK, but that noise is killing the entire office. How is the front glass attached? Glue? Can’t see that in the break down guide. Anyone else seen this? Thanks Here is a video of the issue. YOUTUBE Video
Do you live near rattle snakes ;-} Sadly, you guessed it, the power supply is starting to fail. Is it still covered under warranty? I would still try an AppleStore first as they may have an extended warranty program for this problem.
Check this page out: https://www.instructables.com/id/Fixing-…
Charge your macbook with it’s own power cable, don’t use the thunderbolt display’s magsafe cable. By using the independent cable charger to plug my laptop it completely stopped the noise of the thunderbolt screen.
My 27 LED Cinema Display was making a really loud buzzing noise all day. The sound was emitted from the left side of the monitor (the location of the PSU). I found that unplugging the monitor for a day or two solved the issue. I imagine this allowed the components in the PSU to discharge. Prior to that, I had always left it plugged in. Best to switch it off entirely when not in use. Hopefully this helps someone.
This issue can also be the EMI filter. This is the actual AC inlet. There are also capacitors and other passive components inside here. If the earth lead from this is also not firmly connected you may get the same buzz shown in this video. Otherwise as others have noted, it is the power supply. You can solve many buzzing issues with reapplication or additonal application of neutral cure silicone or potting compound. You will find quite a bit on there already (those white globs). Just add some more around the transformers, between any larger capacitors that might likely be vibrating against each other. Dont use acidic cure silicone or you will corrode the insides of the machine!
I took mine into a apple specialist and it’s not the power supply. It’s the motherboard that has gone bad and making this noise. I was quote $450 + tax to get it fixed.
