LG 52LD550 Scrambled Picture


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LG 52LD550 Scrambled Picture

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ixxbigdxxi
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May 16, 2014, 6:04 AM

Post #1 of 15 (9802 views)
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LG 52LD550 Scrambled Picture	Can't Post

I was watching TV one day and suddenly the screen went completely scrambled. It cleared up shortly after then went back again and has been like that since. I unplugged for 30 mins but this did not help. I'm not an expert on TVs but from after opening it I only see 2 boards the main board and tcon board that could be the problem. Anyone know which board would cause this issue? Pictures below. Thanks!

flyatyou66
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May 16, 2014, 9:36 PM

Post #2 of 15 (9778 views)
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Re: [ixxbigdxxi] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

These pictures are with the cable disconnected? Do you have sound?Any buldged caps on psu?Have you tried touching the flex cables, especially the ones from main board to t-con board including the 2 brown cables that go to screen.

ixxbigdxxi
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May 17, 2014, 2:14 AM

Post #3 of 15 (9769 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

The first picture was a commercial. The second was the tv turned to a channel with snow. I do get sound and such. Menu and volume controls also come up scrambled. I did reseat the cables going from main board to tcon board and tcon board to panel with no luck. I did not remove the gray plastic from the power supply to check for bulging caps. Will do that and report back.

ixxbigdxxi
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May 17, 2014, 9:22 PM

Post #4 of 15 (9753 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

I checked the caps and all looked ok - none looked swollen. I did notice a couple of fuses. Would any of those blowing cause this maybe. I didn't have my multimeter to test continuity but I will try to do that soon. Pics below are some close ups of the boards if they help any. Leaning toward a bad tcon board but not 100%

flyatyou66
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May 18, 2014, 3:50 AM

Post #5 of 15 (9740 views)
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Re: [ixxbigdxxi] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

I don't think it's your t-con. I think it's your power board.I noticed capacitors in the top right corner that i have replaced before on power boards.Do the top of those cap feel hot or very warm.The way you described it is more of a capicitor problem , with picture failure.
Let's look at it this way:- If the power board cannot supply propper voltage to the mainboard. then the t-con cannot do it's job. I have replaced t-con and logic boards, only to end up in same place.
Need to do voltage test on psu to find out where you stand.

flyatyou66
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May 18, 2014, 5:18 PM

Post #6 of 15 (9723 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

I took a close look at your t-con board trying to find a fuse but no luck.However i saw a smd led.This is a green surface mount led that tells you if your t-con is working.It should flash i per second or some stay on all the time. Question:Does the light come on and flash or just sstay on? (It's the 6 pin surface mount device that is located to the left bottom corner of the large ic in middle of board.

jts1957
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May 18, 2014, 5:34 PM

Post #7 of 15 (9719 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Quote

I took a close look at your t-con board trying to find a fuse but no luck.

F100 - bottom right corner. Tongue

-------------------------
Location: Far, Far Away

flyatyou66
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May 18, 2014, 11:26 PM

Post #8 of 15 (9712 views)
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Re: [jts1957] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Thanks

ixxbigdxxi
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May 19, 2014, 5:15 AM

Post #9 of 15 (9704 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

I never noticed a light on the tcon when I took off the cover but it usually has a guard on it. I will check it without the guard next. Also will check to see if the caps are warm or hot and check that f100 fuse that was pointed out. I will be out of town until Friday though. Thanks for taking the time. :D

ixxbigdxxi
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May 24, 2014, 1:53 AM

Post #10 of 15 (9655 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Checked all the fuses today with the multimeter and checked all the voltages coming out of the power supply per the voltage markings by the connector going to the main board and all came up exactly where they should be. I think I have located the problem though. After being on for a bit I noticed the TV was starting to clear up. I started to mess with the t-con board but had no affect. Same results with the power board. When I went to the main board and touched the big heatsink there, they picture scrambled again. After a while, it cleared up and when I pressed on the heatsink slightly the picture scrambled again. Guessing bad solder under the chip? Looks like I need to replaced the main board Frown

(This post was edited by ixxbigdxxi on May 24, 2014, 1:55 AM)

ixxbigdxxi
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May 24, 2014, 2:41 AM

Post #11 of 15 (9649 views)
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Any idea on where to order one? Seems every site I checked it was out of stock. EBU60852913 EAX61746403 are the numbers on see on the board. Thanks again.

flyatyou66
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May 25, 2014, 12:35 AM

Post #12 of 15 (9629 views)
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Re: [ixxbigdxxi] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Shop Jimmy, they should have it.

ixxbigdxxi
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Jun 8, 2014, 9:24 PM

Post #13 of 15 (9523 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Got the replacement board in this week and installed it but I believe the board is no good. The picture does come up clear but it makes the backlight board hum slightly and the backlights will turn off and on a few times then the tv turns off with a blinking red indicator light. Not sure if there is a short or something. Below are some videos with the old and new board installed. The first one is the tv starting cold with the original board. The second is after the tv has been on for a few minutes and the board warm. The third is with the new one installed. As you see the picture is clear but the backlight keeps going on and off then the blinking red light.

Tv with original board installed: http://youtu.be/ttcjY8h0lco
Tv with original board 2: http://youtu.be/nY1zsffMA34
Tv with replacement board installed: http://youtu.be/2f5hs3GZyqs

(This post was edited by ixxbigdxxi on Jun 8, 2014, 10:06 PM)

flyatyou66
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Jun 10, 2014, 9:00 PM

Post #14 of 15 (9485 views)
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Re: [ixxbigdxxi] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Good menu display means it is not the t-con. If menu display is scrambled it's mainboard, due to excessive heat to main ic on main board

ixxbigdxxi
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Jul 2, 2014, 9:16 AM

Post #15 of 15 (9354 views)
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Re: [flyatyou66] LG 52LD550 Scrambled Picture [In reply to]	Can't Post

Got very lucky and found the tv on craigslist! Panel was cracked and was selling for $100 obo. Ended up getting it for $75! Took out the main board and put it in and all is working great! Thanks for the help! Smile

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