MP 1,1-5,1 Mac Pro 5,1 PSU humming noise after revived from catastrophic hardware damage

[DamnTrain]

So the background story is, I got a Mac Pro Server (5,1 MC915LL/A) that had a very harsh life: It went right into a huge bang and tripped the circuit breaker of the house after being powered on for the first time. The reason is left unknown but probably due to internal condensation as it's just being lugged in from about -10°C environment to room temperature. Took it to a mending shop, diagnosed that the CPU tray is dead but the PSU is okay, replaced the CPU tray and it's back to life.

But now despite the system itself runs without any problem, the PSU would generate humming noise randomly, both when the system is turned on or not. Is this normal behavior? If not, does that mean the PSU is still left with trouble, and what is required to do to ensure safety if that is true?

 

[amstel78]

If it's not the fan, which I'm assuming it's not, could be capacitors, inductors, or coils emitting noise. Can't help you much further than to provide the following link which might help you diagnose what you're hearing.

Fixing Coil Whine: A Clear Explanation & 15 Effective Solutions | Clever Creations

Do you have a high pitched sound coming from your computer or laptop? This can be coil whine. This article has everything you need to fix it. Read more!

clevercreations.org

 

[mattspace]

PSU would generate humming noise randomly, both when the system is turned on or not. Is this normal behavior? If not, does that mean the PSU is still left with trouble, and what is required to do to ensure safety if that is true?

My machine makes a faint hum from the PSU whenever it’s plugged into live power (240v through a UPS), and has done for the ~ 8 years I’ve owned it.

 

[DamnTrain]

If it's not the fan, which I'm assuming it's not, could be capacitors, inductors, or coils emitting noise. Can't help you much further than to provide the following link which might help you diagnose what you're hearing.

Thanks mate for helping out, but unfortunately, I am not really capable of replacing or reseating this kind of high voltage part. As it's not harmful, just leave it there.