Mulja tv repair portal
Equipment Repairs => Lcd monitors and laptops repairs => Topic started by: geq on July 11, 2019,09:41:59
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Hello! I'm troubleshooting an LG Flatron W1942S LCD monitor. It didn't power up, sometimes after unplugging and plugging it again it showed the LG logo for a second or less. I disassembled it and noticed several capacitors, most noticeably the big 450v one, were swollen, so I changed all the electrolytic capacitors on the power supply board. Only one capacitor is different, the 450v 68uF (I think, I've already reassembled it) is now 450v 100uF. Now it works, and the image quality has really improved (it was grainy and the colors were off, now it's perfect and bright). But after being powered off overnight, when I plug it, it shows a black screen (it's not off, you can see it's black with the backlight on) and the power button is unresponsive and its light is off too. If I unplug it and plug it back a couple of times, it eventually starts normally. It displays a diagonal rain (like color noise) for a couple of minutes. After a couple of minutes you can turn it off and on, unplug it and plug it again, whatever you do it always starts up normally and with a clear image. Of course I'm not looking for a long distance solution. I would like to have suggestions about what should I check. Thank you very much.