LG37LF66 - Broke it more while repairing.. what is the broken part?

[zelig880]

Dear all,

First of all, thank you so much for the great posts. I have been reading the post quite for a while, as I use to repair staff on my free time as I am a DIY amatour.

Usually i find all the answer for my problem and therefore I never wrote a new post, but unluckily this time I didnt find what I was looking for and need your help to find the solution to the "black" tunnel....

I have a lg37lf66 - I bought it broken to repair it...( i know its mental lol)

When i took the tv neighter the image or the sound was working, so i opended it up and found out that there were broken capacitor in the power supply and in the backlight inverte.

After I changed this capacitor the Tv started to work and would eventually love image after 20-30 minutes...

this is the video of the problem that was showing...

http://www.youtube.com/watch?v=azHTYOXhTps

HERE come the best part...

Searching around the internet I found a thread that explained my same problem and gave a very simple solutuion for the problem.. use a wet finger on the T-con until the tv was showing a good image...

Well.. i did it.. it was fun as I was having some small shocks here and then ( DO NOT DO THIS.. LOL) But I found what was the issue.. infact by placing my finger on the black thinghy ( dont know the name) showed in the pic below the tv was working fine...



So I decided to fix it ( always as suggested on the other post), by using a pencil!!!.. It said that by using the pensil was a good and easy fix to the issue.. So i did it and believe it or not IT WORKED! AHAHA...

Unluckily not for long.. the tv worked for almost two hours with no problem at all.. and If it was starting to flicker I would just had reuse my pencil...

At one point the tv was flickering as in the video so I went to use my pencil and... BOOOOM...

There was a spark on the pencil that touched the little leg and the tv turned off by itself!!!

post boom effect..

If i switch the tv on it starts and the sound is perfect.. I can see a glow in the corner of the tv, so I assume that the backlight is working...

THe problem is that now the TV is completly black and there is no way to turn the image on again!

Important note.. before if I was passing the pencil on the t-con I could see spark.. now the sparks dont happen anymore..

I am keen to buy a new tcon but I would like to ask you guys if you think I have broken something elsewhere now, or is just the tcon...

Please let me know if you want me to make any extra picture or test..

Thank you again and sorry for the long post but i thought was important to tell you all the details..

Byeeee

[Caleb]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

the fuse on the tcon is likely blown, possibly lots of other components. You may be able to replace the fuse and get a picture back but I would bet your gonna need a new tcon.
BTW sticking a wet finger in live electronics is a very bad idea, good way to get entered into the Darwin Awards

[budm]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

Pencil lead is made of Carbon which is conductive.

[jose6326]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

i would like to see this thread where it tells you to put a wet finger in a live circuit. that is just crazy

[zelig880]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

hi all..

thank you so much for the reply, i know i have been silly, but hopefully i havent made too much damage!!

I have bought a t-con board now, and should receive it on tuesday... I have also checked all the power voltage on the cables and they all look good at the moment...

is there anything else you suggest me before I change the board? I promise I will not do anything stupid anymore...

I know the wetfinger was a very stupid idea, but it actually did the job, it was my fault, i should have bought the t con immediately instead of playing around with the pencil...

Just for a bit of fun, this is the thread were i read about the web finger.. lol

http://www.agoraquest.com/viewtopic....38211&forum=34

[zelig880]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

Dear all.. I am here with a little ( big) update...

I really dont know if at this point is fair to open another thread because the initial post doesnt help people to find the issue..., but until i dont want to mess up with the forum rules so I will stick with this until someone gives me the ok to do so...

THE UPDATE...

i have changed the t-con with a new one.. and unluckily the initial problem is there again.

SYMTOMS:

- I can switch the tv on and everything will be fine for around 30-60 minutes.. no problem, sometimes on distortion after 10 min but for the rest is fine...

- after that time the tv starts to play up, the image gest distorted, hundreds of horizontal lines all over the screen and double image. Occasionally the screen becames black but then he pop back again.

- if the image that need to be shown is all white or basic color the image shows almost of.. but as soon as the image change the distortion continue...

- if i switch the tv off and on again immediately the problem is still there..

- if i keep the tv off for some time and swithc it on again the image is fine..

WHAT I HAVE DONE SO FAR...

- changed 2 blown capacitor on the power supply.
- changed 2 blown capacitors on the backlight
- change the t-con.
- visual chekc of capacitors and voltage as written on the board ( no specific voltage of all componend as i dont know how to do it....

THANKS FOR THE HELP IN ADVANCE!

(i am trying to upload a new video from my phone but i didnt manage so far)

[freakaftr8]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

Id get.some freeze spray at this point and spray the panel top and sides while its on and see if the problem goes away temporarily.

[Glitcher]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

I would guess you probably have the bad tab bonds problem.

[zelig880]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

Thank you so much for the fast reply for you both...

what is this "bad tab bonds" problem? can you send me a link with a discussion of it " hopefully with a solution...

And for the freezing spray, where shall i spray it ( even if i havent got it, i need to buy one).. on the back of the tv or on the actual lcd...

the lines are always horizontal,... does it mean i need to focus on the side panel?!

[zelig880]

Re: LG37LF66 - Broke it more while repairing.. what is the broken part?

here I am again...

I have somke updates and the problem.. and this time I really hope you could give me some more information on how to progress my repair, before I buy any more pieces..

I tried to look for broken bond problem.. and Unlukily I dont think this is the right problem.. in fact I didnt manage to make the tv any better acting on the tabs...

I found something else, there is a part of the power supply, the one that change dc to ac) that seems different from the others ( like if it has been changed already) and if i make keep that part ventilated, the tv works perfectly...

This is the picture of the piece I think is faulty...

http://www.dropbox.com/s/ragvzvkp4o0p7vo/2013-10-06%2016.14.24.jpg

Any idea on how to make sure this is the problem? Can i do anthing with the multimeter with this part?

Any advice welcome. thank you so much..