Have above ATX power supply from a friend. Symptom is tripping home circuit breaker (however, internal fuse seem good).
1. Initial trouble shooting found input AC Live and Neutral lead is 0.02ohm. finally traced to FET Q301A shorted. It is a 5R199 N+channel FET. I replaced both Q301A and Q301B to 20N60C3.
2. Short circuit condition for input circuit is now fixed. However, the PSU still cause home breaker to tripped (fuse in PSU still good, quite surprised).
I failed to understand what else can cause a tripped to home breaker as clearly the current ahould be quite high and circuit breaker is fast to react to it vs fuse.
Do anyone happen to have a pointer on how to obtain a copy of circuit diagram for above power supply? It will be quite a waste to scrap away this nice power supply. So hope there is a chabce to have it fix.
1. Initial trouble shooting found input AC Live and Neutral lead is 0.02ohm. finally traced to FET Q301A shorted. It is a 5R199 N+channel FET. I replaced both Q301A and Q301B to 20N60C3.
2. Short circuit condition for input circuit is now fixed. However, the PSU still cause home breaker to tripped (fuse in PSU still good, quite surprised).
I failed to understand what else can cause a tripped to home breaker as clearly the current ahould be quite high and circuit breaker is fast to react to it vs fuse.
Do anyone happen to have a pointer on how to obtain a copy of circuit diagram for above power supply? It will be quite a waste to scrap away this nice power supply. So hope there is a chabce to have it fix.
Comment