Sony CR44 PSU from Mac SE - Left on with no load over night

[BeigeBoxSC]

I stayed up late recapping the PSU because I was on a roll. I tested it and got good voltage. But accidentally left it on overnight with no load. D'oh!

Now the voltages are low and all wrong. I pulled off and tested five of the new capacitors but found them to be still normal.

Replacing capacitors is really the only thing I know to do with my YouTube education. I'm hoping some pros can offer me guidance on what other components I should check and how to check them.

Thanks!

 

[JDW]

Honestly, I've never left my Sony CR44 PSU powered-on in a No-Load condition for more than a few minutes to take measurements. I therefore have no personal experience to drawn on to say why your PSU would have failed, and certainly after you replaced ALL the electrolytic capacitors.

Was the removable door which acts as a heatsink left removed overnight? I doubt that would kill the PSU in a No-load condition, but I am just curious.

When you recap the PCB, you must remove the heatsink clip on one 3-legged component on the left side of the circuit board, because that locks the PCB into the metal chassis. After your recap, did you remember to put that component back in place with its gray heat-pad too? I'm not sure if that heat-pad was intended to replace thermal paste alone, or if it actually acts to electrically isolate the component too. Because if that pad isolates the component from the metal chassis, and if you forget the pad and secure the component's metal back to the chassis, maybe that would fry that component? Again, I'm not sure, but just thinking out loud.

Was anything hot when you found the PSU in the switched-ON position the next morning?

What if you leave it disconnected for an hour, then switch it on and do tests again?

Were there any bad smells?

Do you happen to have a Thermal Camera which could help you identify excessive heat on the PCB?

What happens if you turn down the little POT which lets you adjust voltage? Any change or improvement?