I'm very new to working on these
I'm working on a TX650W that cycles on/off repeatedly, as per the inner timing of the PS229 supervisor IC.
Everything seems more or less fine when I've poked around with a DMM. With it hooked to a PC, it appears to hit all the correct voltages. I've used single capture triggering to look at most everything on the 14-pin DIP PS229 and the secondary side of the 3 opto's. Nothing is horribly wrong, there's been some spikes I wonder about but IDK.
So I went ahead and desoldered all the main output caps, and they all read fine with an LCR meter, and DMM. They are all 2200u and 3300u.
There's a 100u cap that might be near the ESR limit, depending on the chart I look at. It was 100u 25V with an ESR of 0.134
The big bulk 390u 400V is great.
So I desoldered all the main sec. rectifier diodes, and they are perfect, nicely matched
So I checked some sec. SMD caps and I think it's ok. (2 looked funny and I broke them getting them off, but they 'were' ok, the LCR meter wasn't reading the caps in-circuit)
I've mapped most of the PCB, but I've not tried to calculate hardly anything, or measured every little voltage yet. I want to tho.
The LM393 fan controller had power, and the PTC (or NTC) is ok. There's a few TL431 circuits I've mapped, and they seemed ok on the surface to me anyways.
I'm assuming the pri side is fine, IDK.
I'm having fun but I'm really walking in the dark at this point. I should start injecting voltages and calculate a bit to look at some networks, while the diodes are out.