Hello people,
Some days back my computer went off and didn't start at all after doing all sort of things from outside, so i decided to open the CPU and check what the actual problem is. Plugging away every pins from motherboard and other components i checked the voltages at every wire that comes out of the PSU and found nothing. After reading some articles on Google i found that after shorting the green wire and any of the ground (black) wire the PSU will turn on, i did that too and checked tge voltages again and found nothing.
Then i open the PSU and after checking all the components on the PCB found that nothing. So i de-soldered the main switching MOSFET and 3 schottky diodes mounted on the heat sink.
Voltage drop across the MOSFET was according to what is specified on the datasheet but the 3 schottky diodes behave unusual. They are not completely short but they show very less forward voltage drop.
Voltage drops are as follows-
STPS30L45CW
Vf=0.120V
STPS20S100CT
Vf=0.295V
B30H60G
Vf=0.170V
PS. Fuse, rectifier IC and the main big filtering capacitors are okay.
Some days back my computer went off and didn't start at all after doing all sort of things from outside, so i decided to open the CPU and check what the actual problem is. Plugging away every pins from motherboard and other components i checked the voltages at every wire that comes out of the PSU and found nothing. After reading some articles on Google i found that after shorting the green wire and any of the ground (black) wire the PSU will turn on, i did that too and checked tge voltages again and found nothing.
Then i open the PSU and after checking all the components on the PCB found that nothing. So i de-soldered the main switching MOSFET and 3 schottky diodes mounted on the heat sink.
Voltage drop across the MOSFET was according to what is specified on the datasheet but the 3 schottky diodes behave unusual. They are not completely short but they show very less forward voltage drop.
Voltage drops are as follows-
STPS30L45CW
Vf=0.120V
STPS20S100CT
Vf=0.295V
B30H60G
Vf=0.170V
PS. Fuse, rectifier IC and the main big filtering capacitors are okay.
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