Had a broken HP-Photosmart printer power supply. Its parameters are input 100-240VAC 50/60Hz and output 32VDC 625mA. Condition - not working. My first steps were measuring output voltage on DC cable on pins 1 and 2. No output. Green LED is not on also. Checked AC cable for continuity. AC cable was OK too.
Next steps apparently was to suspect inside electronics. I started to open supply enclosure hoping on easy fix. You need to unscrew hex bolt from bottom. Enclosure is holding on some clips what I did not know at that moment and made unnecessary damage to plastics. Later had to use an epoxy glue when assembling back.
Shortly problem were short diodes (1N4007) in diode bridge, which led to burnt fuse. It can easily be checked with multimeter in resistance/diode mode. Diodes were in short, and fuse in open.
In picture below you can see bad components.
At the moment I had no exact parts available, so I replaced 1N4007 with 1N5408 and fuse with round one (same rating F4A) with piece of wire soldered to one of outputs to reach holes in PCB.
Here is how board looks with replaced alternative components.
Power supply is functional again. Hard to say to what was the main reason for broken diodes. Maybe some voltage or current spike while turning on...
