I have an old switching power supply for HP 712/60 workstation (+5V, +3V3, +12v). It was working about ten years ago when i've last tried to boot the system, but now one of the output voltages is at half of the nominal value (12V output is at 5.6V). I have replaced all of the electrolytic capacitors in the SMPS, and resoldered all points on low voltage section – still 12V output is at 5.6V. What to look for next?
General question – SMPS has output voltage lower than nominal – what troubleshooting strategy should i take to find the culprit?
Electronic – SMPS output voltage too low – what to look for
switch-mode-power-supplytroubleshooting
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Best Answer
One of the most important troubleshooting procedures I do, is to measure the resistance between output rails to the ground. If the resistance is too low, then one of semiconductor parts on the secondary side; e.g. diodes or MOSFETs might be broken. Otherwise, which I'm not so practical with is the capacitors also might be faulty.
Good luck,