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joel321

@sbcglobal.net

I foxed my LCD TV, oops.

I was trying to install a laptop fan to the main board but I made a mistake...oops...i momentarily plugged it in while I had it apart to check something but I forgot to unplug it before tinkering with it some more...

this is the end results...




what I did before noticing it was still plugged in, was pull off the two cable ribbons from the top and then plugged them back in...




that's the only thing i did....anyone know what I may have fried?

Also, anyone knows of good reputable TV parts website?

the main board part is EBU60943905

the TV model is 42LD520

Many thanks in advance.


TheMole

join:2001-12-06
USA
Dumb question: why were you adding a laptop fan to the board?


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to joel321
Those ribbon cables can be finicky. Before replacing the more expensive components of your TV I would suggest:

1.) turn off the power
2.) double check that the power is turned off
3.) disconnect the ribbon cables one more time
4.) carefully examine cable ends and connectors for any dirt or damage
5.) even more carefully re-seat the ribbon cable
6.) after closing the connectors verify that the ribbon cables are seated properly
7.) cross fingers and power the TV back on

A magnifying glass is a useful tool in steps 4 and 6.

Good luck.
--
Got some spare cpu cycles ? Join Team Helix or Team Starfire!

Mister_E

join:2004-04-02
Etobicoke, ON
Reviews:
·Bell Sympatico

1 recommendation

reply to joel321
For the two ribbon cables:

Did you forcibly pull them out of their sockets? If so, that could be your problem.

The darker black/brown portion of the socket is a plastic tab that should be carefully and gently lifted up to free the ribbon cable properly. With the tab in the up position, you can then slide the ribbon cable in properly and secure it down by closing the tab again.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

1 recommendation

reply to joel321
said by joel321 :

what I did before noticing it was still plugged in, was pull off the two cable ribbons from the top and then plugged them back in... that's the only thing i did....anyone know what I may have fried?

Those ribbon cables seem to go directly to the IC under that large heat sink below the memory IC. That could mean it is the main display driver for the TV.

Input/Output pads of complex ICs are not really designed to handle "hot plugging" ... which is what you did. Follow leibold See Profile suggestions and hope it will work.

If it does not, probably it is not worth it to get that huge surface mount IC replaced.


joel321

@sbcglobal.net
i have been busy and have not had the time to troubleshoot and I had an allergic reaction yesterday but im good now....

quote:
Dumb question: why were you adding a laptop fan to the board?
1-heat dissipation = longer life...keep those capacitors cool.
2-i like to take things apart and see how they work.

quote:
1.) turn off the power
2.) double check that the power is turned off
3.) disconnect the ribbon cables one more time
4.) carefully examine cable ends and connectors for any dirt or damage
5.) even more carefully re-seat the ribbon cable
6.) after closing the connectors verify that the ribbon cables are seated properly
7.) cross fingers and power the TV back on
I have a feeling I shorted something out...worth to check...only a few screws hold the back panel on...with my 12v dewalt screw driver.. easy. will try tomorrow or over the week end.

quote:
For the two ribbon cables:

Did you forcibly pull them out of their sockets? If so, that could be your problem.

The darker black/brown portion of the socket is a plastic tab that should be carefully and gently lifted up to free the ribbon cable properly. With the tab in the up position, you can then slide the ribbon cable in properly and secure it down by closing the tab again.
I did lift the plastic tabs...good suggestion, but i'm leaning more a short...will double check if the tabs are well closed.

quote:
Those ribbon cables seem to go directly to the IC under that large heat sink below the memory IC. That could mean it is the main display driver for the TV.

Input/Output pads of complex ICs are not really designed to handle "hot plugging" ... which is what you did. Follow leibold suggestions and hope it will work.

If it does not, probably it is not worth it to get that huge surface mount IC replaced.
yes that is what I did hot plugged them back in...in the beginning I could see half of the screen only...that made me think that one ribbon handles half of the picture...but then after a few minutes the other half went as well. Now as curiosity, I will take the heat sink of that chip and see if I can find it online...but i'm leaning more towards needing a whole board...

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
said by joel321 :

Now as curiosity, I will take the heat sink of that chip and see if I can find it online...

I am very curious to know which IC they used. So if you do remove the heat sink, post a clear photo of the label.


joel321

@sbcglobal.net
here is a picture of the chip...i haven't had time to google for any info on it though...




Fishead1
Premium
join:2001-05-08
Bronx, NY
Reviews:
·Verizon FiOS
reply to joel321
I had something very similar happen to the video card in my PC and after discussing it here »Video card Problem down as the first picture in that post didn't show the lines but the others did.
The consensus seemed to be a video card memory problem.I had a friend lend me an old video card and the problem disappeared.
I have a new video card on order.
I think you'll have to change out the whole board.Something in the video chip is fried.

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to lutful
That is a full custom ASIC, probably built by LG's original Korean semiconductor fab Global Unichip. They have moved to TSMC of Taiwan in late 2012.

Anyway, only LG certified repair shops will have that IC.


joel321

@sbcglobal.net
reply to Fishead1
quote:
I think you'll have to change out the whole board.Something in the video chip is fried.
yes. i'm just having a hard time who to trust to buy from. i already got burned once and never got my money back. also, i have never bought anything from ebay so i don't know how that works. i'm not in a hurry to fix it..so i'll search around...i see sears parts has it for $175 but never bought there either. hehehe this TV is almost brand new it still has the plstic protecting around the tv...so before i call it quits..i don't mind spending 200 bucks to bring it back to life...well see...i will post back if successful.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
I don't mean to scare you, but also have a look at the other end where those ribbon cables connect to. Hot plugging those cables could have damaged components on either (or both) ends of the cables.
--
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joel321

@sbcglobal.net
good thinking...i took a peek and most i saw where micro resistors...the ribbon cables that go into the LCD panel apear to be glued, sandwiched in between two panes of glass...guessing no electronic parts go in there just the pixels and liquid and stuff..




my gut feeling is telling me that the brain would give first that the other components...

i will risk the 200 bucks and post back if successful.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to joel321
1 - I hope you learned your lesson: Don't fix it if it ain't broke.
I don't blame you or insult you in this, I have done the same mistake several times (fixing what ain't broke and breaking it).

2 - I'd go to AVS forums, they have a LOT of users and a bunch of them are pros regarding fixing TVs.

3 - Depending on the AVS forum response, if it isn't clear cut, I'd cut my losses and toss the TV in the garbage. 200$ is a lot for a guess. It could be a cable, two cables, one of the LCD controllers, who knows! Do you feel like you can control the TV even if you can't see anything? (hear audio, switch channels etc) because if you can't control it, it might be the main board which would be more expensive to replace than what the TV is worth.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
reply to joel321
said by joel321:

quote:
Dumb question: why were you adding a laptop fan to the board?
1-heat dissipation = longer life...keep those capacitors cool.
2-i like to take things apart and see how they work.

1 -- May not have achieved longer life
2 -- Much better to take things apart that don't work and try to make them work than the other way around