Hope everyone is well and thank you in advance for the help.
I'm currently working on an 22” LG TV / Monitor that is presenting with the standard 2s to black symptoms. When the power on is pressed everything boots just fine – Image shows for a second and then backlight turns off and with a flashlight you can still see the image.
I started by removing all the electrolytic caps and testing them with my meter and all the capacitances were good.
I proceeded to unplugging every individual lamp and testing again (4 in total) and again, fault persists so I can either assume all the lamps are ok… or all are broken. (I am going to assume they are all good).
I have tested the Fuse and the diodes in situ and again all check ok.
Next I probed the output voltages into the signal board and all are either: 15V, 5V or 3.3V as specified on the markings so that seems ok which makes me think that power board is ok and the problem lies with the inverter section of the board?
Lastly I probed the two inverter transformers on the secondary side and again, both show about 1.1K
Now after that I am fairly stumped as to what the problem could be – If there is absolutely anything you would suggest I would greatly appreciate it.
Warm Regards,
Demon
(P.S - Those are pen marks, not burn marks on the transistors on the underside)
I'm currently working on an 22” LG TV / Monitor that is presenting with the standard 2s to black symptoms. When the power on is pressed everything boots just fine – Image shows for a second and then backlight turns off and with a flashlight you can still see the image.
I started by removing all the electrolytic caps and testing them with my meter and all the capacitances were good.
I proceeded to unplugging every individual lamp and testing again (4 in total) and again, fault persists so I can either assume all the lamps are ok… or all are broken. (I am going to assume they are all good).
I have tested the Fuse and the diodes in situ and again all check ok.
Next I probed the output voltages into the signal board and all are either: 15V, 5V or 3.3V as specified on the markings so that seems ok which makes me think that power board is ok and the problem lies with the inverter section of the board?
Lastly I probed the two inverter transformers on the secondary side and again, both show about 1.1K
Now after that I am fairly stumped as to what the problem could be – If there is absolutely anything you would suggest I would greatly appreciate it.
Warm Regards,
Demon
(P.S - Those are pen marks, not burn marks on the transistors on the underside)
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