Oscilloscope PSU whining noise? Answered
My oscilloscope is a Philips PM3055. It's a CRT type with a modular internal design, one PCB is the PSU, one is the front panel, a few are TTL, etc.
When I try to turn it on the screen is blank and the PSU makes a whining/whistling noise, and does not function.
The whining persists regardless of connection to other boards and mains ground.
(mains ground is normally not connected to the PSU, but there's a connector)
I have found no bulging/leaking capacitors (though I have no way of testing capacitance) or other visible damage,
except for cracked plastic on the front panel. But that's merely cosmetic.
Replacing the PSU is not an option, since the scope is old and obsolete. Neither is buying a new scope. I am broke.
All help greatly appreciated!
If you help me fix it, I might just send you one of those fancy patches.
I can only provide cellphone-camera quality pictures at the moment, and for that I am sorry.
[Edit / update]
I contacted Advance Product Services, And they sent me the complete service manual for the scope, free of charge.
Those guys are awesome!