EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: Gcsillaz on April 23, 2021, 07:58:23 pm
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Hello everyone!
Friend of mine described that while he was sleeping suddenly he heard a loud "zooooom" followed by a big "puff" and woke up. When he turned the lights on he saw a lot of smoke coming from his PC (Which he turned off before sleeping, but was still connected to the outlet and PSU switch on).
He asked if I could take a look at his PSU and see what happened.
Upon opening up there was a lot of electrolite liquid and the bulk cap had poped off... Also the diode and the mosfets of the PFC part are all shorted (remove from the pcb to test)
That was all I could find and test upon inspection...
I would like to know if you guys could help me regarding two topics.
1 - The diode is a STTH806D and the FETs are STF13NM60ND. I've searched for them on the area but could not find them... From your guys experience do you think I could replace them for: FQPF10N60C (Little lower Amp + Higer RDs(on)) and for the Diode I have two options which are RURP1560 (0.4 higher Vforw and 18ns Higher reverse time) and the MUR 860.
2 - What could possible be damaged fromt his failure? The secondary side could?
Thanks in advance!
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you can usually omit the PFC completely and the supply will run (with bad power factor), so start with replacing the bridge(did it also die?) and main cap
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The PFC controller and it's associated components could be suspect too and should be checked before replacing the power components.
Whenever I see the bulk capacitor in a PFC power supply explode, it's usually a result of a significant over-voltage due to the PFC boost converter going open-loop for one reason or another. An open resistor or solder connection in the feedback loop is all it takes!
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Sorry, I wasnt too clear. Of course remove all the PFC components, leaving just the rectifier and main cap before the actual power supply stage.