LG 32LC52 no picture
Good day folks. I need a bit of help with this LG TV which may have multiple issues. When the chap first brought it in, I could see the backlight turning on and the TV appeared to be on, but there was nothing on screen. A while back, I managed to fix an older Samsung which had the same issue by replacing a dead regulator on the t-con board, so I hoped this one had the same issue. There was a slight change of plans however when the next day I plugged it in again and the green light just kept flashing - no other reaction. I took the cover off and immediately noticed a lot of bulging caps. Replaced them and of course, still nothing: it went back to that state where it powers up quickly, the green light stays solid, but there's nothing on screen.
At this point I wasn't sure whether it's the T-con, the main board or the PSU itself which still had a problem, since all of them had something unconvincing about them, as follows:
-the 3.4v rail on the PSU doesn't come on....after a bit of fiddling, I connected the 5Vsb rail to the 3.4v ON pin on the connector and now I got 3.4v where it should go, so let's assume the PSU is fine for now.
-this bring us to why the main board is not sending that 3.4v ON signal by itself and required me to manually jump it
-even with 3.4v now present, there was still no picture. I even applied 3.4v from an external supply and the same thing happened.
-the T-con board seems fine, except for one thing I noticed: that 1.8v test point I pictured up close only reads 1.5v which upon closer inspection seems to be coming from the LDO directly next to it. The datasheet for it, confirms it's a 1.5v regulator, so that's most likely fine.
All things considered, I'm leaning towards a faulty main board: it doesn't send any signal to the t-con board (no scope to check this sadly), but combined with the lack of 3.4v I ASSUME that is it. There is a green light coming on near the connector in the top-left (D800 on page 36 of the schematic I posted), but that's about it....it's an EAX32572506. Pictures are pretty piss-poor, I know. Cheers and thanks
At this point I wasn't sure whether it's the T-con, the main board or the PSU itself which still had a problem, since all of them had something unconvincing about them, as follows:
-the 3.4v rail on the PSU doesn't come on....after a bit of fiddling, I connected the 5Vsb rail to the 3.4v ON pin on the connector and now I got 3.4v where it should go, so let's assume the PSU is fine for now.
-this bring us to why the main board is not sending that 3.4v ON signal by itself and required me to manually jump it
-even with 3.4v now present, there was still no picture. I even applied 3.4v from an external supply and the same thing happened.
-the T-con board seems fine, except for one thing I noticed: that 1.8v test point I pictured up close only reads 1.5v which upon closer inspection seems to be coming from the LDO directly next to it. The datasheet for it, confirms it's a 1.5v regulator, so that's most likely fine.
All things considered, I'm leaning towards a faulty main board: it doesn't send any signal to the t-con board (no scope to check this sadly), but combined with the lack of 3.4v I ASSUME that is it. There is a green light coming on near the connector in the top-left (D800 on page 36 of the schematic I posted), but that's about it....it's an EAX32572506. Pictures are pretty piss-poor, I know. Cheers and thanks
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