Hi
I have seen the same fault (see photo) a few times on LG's on this occasion it happens to be a 37" LC55, but have seen the same fault on different models & sizes. I do suspect the video board but wondered if anyone had come across this LG fault. The same fault is on the tuner and HDMI, When you look at the test patterns with the 'service remote'. the colours are fine, sort of hoping that it is a PSU or software fault, but suspect is is the main video or T-con board.
Advice appreciated
thanks
junger...
junger
TV Enthusiast
Last Activity: 04-02-2021, 11:26 AM
Joined: 09-09-2011
Location: Cheshire
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Lg LCD Fault that white flares,I have seen a few times.
Last edited by junger; 09-01-2015, 12:27 PM. -
Re: Lg 37lc55
hi all
The fault has developed further,now I can see in the back, when switched on the hv lights up, after about 10 mins the hv lights strobe/flash and then goes back to normal.
I have replaced the PSU board from my mates LG (same model) and it was the same, so I changed the main board and the fault travelled with the board. so the fault is on the main processing board, any ideas? -
Re: Lg 37lc55
hi
which caps are they, so that I can inspect them closer, Thanks for the hairdryer tip, I will try thatLeave a comment:
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Re: Lg 42" lc55 lcd
Sorry, have been quite ill for some time, but two stents later, better now, so am back
regards
jungerLeave a comment:
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Lg 37lc55
Hi All
I have had a couple of the same model giving the same sympton on
LG 37LC55.
When switched on you get no picture, If the LCD is left on for say 15minutes and then the mains cable is unplugged and reinserted then it works perfectly well. I have looked at the caps on the power board and they are not bubbled/dry.
Any ideas, anything I can try?
Thanks
Junger -
Re: Lg 42" lc55 lcd
Ok, 37" LG has no backlight. The symptom on test is fuse o/c.
The large cap is puffed up, therefore it has probably passed a/c.
One transistor is damaged and one power diode is damaged (shown in the photos).
Replaced Cap, Mosfet and Power Diode on PSU Board (from another unit) and the LCD now has a backlight, have found a supplier for the Cap and Mosfet but cannot find a supplier for the Power Diod, any ideas anyone ?...Last edited by junger; 09-14-2011, 03:33 PM.Leave a comment:
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Re: Can one faulty cap in parallel with working cap cause problems?
ok, the reason for the improvement is that the secod cap is helping with the smoothing, however the faulty cap is probably still passing current though itself causing shutdown/reset, can you cut one leg of the faulty cap?Leave a comment:
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Re: Lg 42" lc55 lcd
Sorry, It is a bit mixed up, I have 2 seperate faults on two seperate lcd's. I will post the correct model and the fault associated with that model.
Regards
jungerLeave a comment:
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Re: Lg 37" 2500 lcd
Hi
Sorry, I have already changed the 10volt caps, that was to demonstrate that the 10 volt caps is not my problem (as I have done a few with that problem see cap1 jpeg which shows a replacement cap). My problem is with a LG 2500, when on analogue there are fine verticle lines down the screen when I switch to DTV, then the lines are there but no channel is shown and the set locks up. to restart the LCD it has to be disconnected from the mains and arial removed before switch on, Very strange, not come across this before. anyone know?
I will try...Leave a comment:
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Re: Can one faulty cap in parallel with working cap cause problems?
The short answer is no, however if the faulty cap is o/c then it should be okLeave a comment:
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Re: Lg 42" lc55 lcd
Thanks for that, If you look at the photos, the PSU problem that I am aware of is going into standby and is sorted by changing the 10volt leaky electrolytic caps (see photos, before and after cap change). The fault that has stumped me is the large cap which is leaking but having changed that cap and the inverter the lamps still do not illuminate. It is the power board because I canged the power board from another LCD and the unit then worked. Any ideas please?...Leave a comment:
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Lg 42" lc55 lcd
Hi all, looking forward to my input into this forum. I am, I have at the moment having difficulty with the power board of a LG 42" LC55 LCD.
The sympton is the LCD switches on backlight does not light,the LCD then goes back into standby
I have replaced the PSU board and that fixed it, looking at the faulty PSU, I noticed that the large cap is bubbled at the top, any ideas please?
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