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.
Check this teardown on how to get inside.
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.
Sadly the warranty expired just a few months ago. Does anyone know where I can get a new power supply? At first I will try the local Apple repair shop.
What happens when the power supply fails with these symptoms? I have one failing and after opening it up and powering it on with my ear next to the power supply board it appears to be coming from the solenoids. Will I be able to order replacement solenoids and will soldering them on be possible?
Power supplies don't have solenoids. They do have transformers, coils, and capacitors which can fail.
These power supplies are not really repairable. Best just to replace the complete assembly. But before you do that did you check the voltages?
Whoops, thanks for the correction. I think I meant inductors or "chokes", which might be what you mean by "coils".
Are you sure the capacitors aren't replaceable? I'm fairly handy with a soldering iron and would rather give it a try before spending $150 on a new PSU board.
If I wanted to check the voltages, where would I connect the multimeter probes and what numbers am I looking for?
The problem is no one has schematics or board views for the power supplies. So you'll have a hard time diagnosing what truly failed.
The other problem is some of the components are hard to find so you run the risk of getting in over your head with costs and still no farther along.
Really, its cheaper just to replace the whole unit than spending the effort.
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.
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!
Klaus M estará eternamente agradecido.