From: supervinx on 1 Apr 2010 12:53 I removed an SCR, 2N5061, with this behaviour: connecting an HD (or a load) doesn't shut off the PSU anymore, but voltage drops from 5 to 4.2, and it's not enough. I moved the trimmer with slight advantage (4.5) then the PSU shutdown again. I had to wait some minuites, discharge all caps before it started too work again. Under the SCR there's a fast switching diode 1N4148F, with a constant reverse voltage of 1.40. When everything goes bad, it's the first to receive 0 voltage. Across A-K of the SCR I read about 4.34 V, G and K are equipotential. May be this is the right zone to investigate ? A friend of mine owns a similar PSU (same PC), working, but he'll be back after easter. Having a similar model could help me tracing down the fault... |