Like it stated in the smps, the same power supply is used in various models such as BH7xxx, BH8xxx, BH9xxx and DH7xxx. Does anyone has any service manuals for any of the said models?
T2 = Q912
T3 = Q913
D2 = D913, with R948 added in series with it
R17 = R907, in parallel with the series'd D913/R948
ZD905 added to limit the max voltage going to the MOSFET gate; FB903 in series with the gate, to prevent high-frequency interference from affecting the gate.
Odds are good the PWM chip is gone as well. Can you still read the markings on it?
T2 = Q912
T3 = Q913
D2 = D913, with R948 added in series with it
R17 = R907, in parallel with the series'd D913/R948
ZD905 added to limit the max voltage going to the MOSFET gate; FB903 in series with the gate, to prevent high-frequency interference from affecting the gate.
Odds are good the PWM chip is gone as well. Can you still read the markings on it?
Didnt realise that LG service manuals are really hard to find. Sighs. Thank god manage to get the manual for DH series that uses the same smps. Now i have identified all the components
Ok time for updates. Have changed all the faulty components. Power is up. Theres standby light on the home theater BUT i measured the voltages on the power board, the voltages on all the pins seems higher than rated as i checked using MM on DC mode. Now thats weird. Check screenshot
Upon measuring using MM on DC mode, these are the voltages im getting
3.8VA im getting 9.3VA
6VA im getting 13.7VA
14VA im getting 31.8VA
Some of the joints on T901 look suspect at least from the photo you provided.
That was when i first took it out. Its all soldered already. Now the board is all good. Just wanted to verify the mismatch of voltages. Dont wanna end up blosing things again. Thats why i dont dare operate the unit yet. For now, i know the power light is there. So there is standby present.
Like it stated in the smps, the same power supply is used in various models such as BH7xxx, BH8xxx, BH9xxx and DH7xxx. Does anyone has any service manuals for any of the said models?
Remove as much of that yellow glue as possible because it becomes conductive when aged.
Remove as much of that yellow glue as possible because it becomes conductive when aged.
All removed. I couldn't turn on the unit. Its stuck at standby. Then later on after a few minutes upon checking all voltages, the standby light vanished as well. Checked for voltages again, noticed all voltages from the psu is reducing drastically with load. If i power on without load, the voltages are stable.
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