Hi all,
Got a used working computer running Windows 7 about 3 months ago. Two days ago, the power supply blew up with loud spark and i immediately shut off the power. It was an unknown brand Tatu (output 450 w).
Upon opening, i found out the two transistors on heat sink 1are fried with burn mark. Replaced the two trans(E13007 type). Also checked if the surrounding components are affected. The diode seems to be working, i pulled one leg off and tested using diode test. One side got reading while swapping test probe shows 1(infinite).
I also pulled out the nearest 2 small caps at C5 and C6, they are both 10uf50v. Capacitance read 10.5 to 11.2 uf while esr from 0.46 to 0.5 (based on these reading, i soldered them back on board).
Later, i pulled the 2nd heat sink out, tested those rectifiers by diode test. Black probe on middle leg while red probe on left and right leg got some reading. From the readings, i guess those rectifiers are still good.
Tested the 16 pin(SDC 7500 voltage pwm),dc test with black probe on pin 7 and red probe on pin 12 shows 15vdc, at pin 14 it shows 5vdc.
Tested the 14 pin (SDP 339 voltage quad comparator), dc test with black probe on pin 12 and red probe on pin 3 shows 5vdc.
For testing this blown power supply, i replace the fuse with a series lamp bulb. Upon switched on power, the bulb lighted for 1 second then no more light. So there is no short. But the output power on the 24 pin still not appearing. Only the 5vdc standby power is detected from the green wire. Any help to revive this psu is greatly appreciated.
Got a used working computer running Windows 7 about 3 months ago. Two days ago, the power supply blew up with loud spark and i immediately shut off the power. It was an unknown brand Tatu (output 450 w).
Upon opening, i found out the two transistors on heat sink 1are fried with burn mark. Replaced the two trans(E13007 type). Also checked if the surrounding components are affected. The diode seems to be working, i pulled one leg off and tested using diode test. One side got reading while swapping test probe shows 1(infinite).
I also pulled out the nearest 2 small caps at C5 and C6, they are both 10uf50v. Capacitance read 10.5 to 11.2 uf while esr from 0.46 to 0.5 (based on these reading, i soldered them back on board).
Later, i pulled the 2nd heat sink out, tested those rectifiers by diode test. Black probe on middle leg while red probe on left and right leg got some reading. From the readings, i guess those rectifiers are still good.
Tested the 16 pin(SDC 7500 voltage pwm),dc test with black probe on pin 7 and red probe on pin 12 shows 15vdc, at pin 14 it shows 5vdc.
Tested the 14 pin (SDP 339 voltage quad comparator), dc test with black probe on pin 12 and red probe on pin 3 shows 5vdc.
For testing this blown power supply, i replace the fuse with a series lamp bulb. Upon switched on power, the bulb lighted for 1 second then no more light. So there is no short. But the output power on the 24 pin still not appearing. Only the 5vdc standby power is detected from the green wire. Any help to revive this psu is greatly appreciated.
Comment