I've got a Fujitsu KS350-1401-H022/03 I'm trying to fix up. I've located some shorted diodes but am having trouble identifying them to replace. Getting dead ends on searches for the part number so far, and as they're shorted I can't identify them by measuring.
VR2 - Marked with 1120·7 (guessing on the 7 it looks a bit wonky)
Currently (before removing these diodes) getting a kind of a quite whiny click from the primary side (hopefully VR2, the other diode nearby measured fine and I've already replaced c5). Got less than a volt metered off all three rails but jumping all over the place (before diode removal).
Last Edit: Jun 27, 2021 0:38:14 GMT by dokidokimask: cleanup D91 and further expanding on what's currently going on.
What are you trying to fix on the power supply? Other than replacing the dodgy PWM, recapping, or replacing blown varistors and fuses, there's not much they need fixing. The PWM issue can also be fixed by adding an extra 2200uf electrolytic cap between pin 2 of the octocoupler (plus side) and DC GND (negative side). When I fix power supplies I replace both the PWM and add the extra cap just in case.
VR2 stands for varistor, it's odd they put a diode instead there...
I don't really understand the question since I said exactly what I was trying to fix. 2 diodes that dead shorted which is all I've found broken so far. Though I did relplace the pwm to be safe at it seemed likely diodes going bad was caused by something else. VR2 likely stands for breakdown diode in this case stackoverflow with a chart. I don't remember if the zener was open or closed but the diode in question read 11ohm both ways.
edit: Yeah the VR thing is weird. VR2 has the same silkscreen layout as the other diodes, but VR1 looks like it's a varister.