Hi,
in this thread was mentioned, that ultrasonic cleaning can destroy electronic components. I did not believe this, until today.
I am currently repairing an Instrument from a seller from Israel, which was extremely dirty inside. (No complain about the seller, I was aware about the state of this instrument)
The dirt (desert sand?) was extremely hard to remove, so I used an ultrasonic cleaner. For some of the modules I needed three cleanings from about 20 minutes to remove all the mess.
Now everything is clean, BUT two modules, that worked before the cleaning, have stopped working now.
The reasons are 9 defective RF Transistors (2N5179) which have an interrupted collector now.
So, be careful, not every semiconductor likes ultrasonic cleaning.