Since i'm kind of broke i had the brilliant idea to go and buy a defective PSU from the local PC parts guy and try to fix it.
I got this pretty nice looking RX-5300 with all the cables for 5€.
As soon as i got it i took it apart in search of bad caps (as you do) but much to my surprise they were all good.
Plugging the PSU into a known good mobo results in a no post, so i took the PSU to the bench and started measuring voltages.
No load 12V and 5V were all good but as soon as i put a 3R9 resistor on 5V it dipped down below 1V and the PSU started squealing and resetting, while it's doing that the voltage on the 5V rail slowly goes up until it kicks back to life and jumps to 5V steady.
Same resistor on 12V makes no difference and only results in a burning hot resistor.
All voltages come from one main transformer so my only guess is that the 5V diode is bad but i measured it at 0.1V, which seems all right for a high current shottky.
I'll go probe some more, meanwhile i'd appreciate any help.
I got this pretty nice looking RX-5300 with all the cables for 5€.
As soon as i got it i took it apart in search of bad caps (as you do) but much to my surprise they were all good.
Plugging the PSU into a known good mobo results in a no post, so i took the PSU to the bench and started measuring voltages.
No load 12V and 5V were all good but as soon as i put a 3R9 resistor on 5V it dipped down below 1V and the PSU started squealing and resetting, while it's doing that the voltage on the 5V rail slowly goes up until it kicks back to life and jumps to 5V steady.
Same resistor on 12V makes no difference and only results in a burning hot resistor.
All voltages come from one main transformer so my only guess is that the 5V diode is bad but i measured it at 0.1V, which seems all right for a high current shottky.
I'll go probe some more, meanwhile i'd appreciate any help.
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