Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

[Michale32086]

Had some issues with this unit before... Before, the right side would be all "blobby" and distorted, but would clear up and have a perfect picture after a while, 10-15 mins...

Pulled it out to work on it some more yesterday and it had the same problem but this time, never cleared up.. So, put it aside over night..

Checked it this morning and when powered up, it had a great picture. So I thought, "kewl!! My TV elves came out last night!!"

No such luck.. After about 20 mins, the right side goes all distorted again..

http://sjfm.us/temp/LN40A-1.3gp

(I know we're supposed to use the ATTACHMENT feature, but didn't see a way to attach videos)

If it's likely a panel/display issue, I don't want to waste any more time with it..

I am thinking (read 'hoping') that it's a TCON issue as I have TCON boards coming out my ears..

[saddle_au]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

Try this.

https://www.youtube.com/watch?v=Qj51BkS9d-0

[Michale32086]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

Thanx, Saddle.. Guess I need to get a can of Freeze Spray..

Is it safe to assume that using a can of air held upside down is probably not a good substitute for freeze spray??

Thanx again..

[tom66]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

This would be an LCD issue, i.e. bad panel. May be fixable by tab bond shim - personally I'm not a fan because I've had bad luck with them myself but others have had some work for some time, so maybe worth a go.

[Michale32086]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

I was afraid of that...

Thanx for the input.. At least I know I shouldn't put too much effort into it..

[saddle_au]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

No. You do not want to risk any residue being sprayed in there.

Also be careful with the amount, start with only a short spray straight after it goes wonky. You are dealing with a very thin glass sheet laminated with some polarising film. Thermal shock breaks are a real possibility.

If it makes no difference, move to the tcon and try again in small sections all over it.

Also, from memory, there are almost no parts on the tab pcb on that screen, but the ribbon connections between the panel pcb and tcon are prone to oxidation discolouration (at the top in the LA40A model probably the same for an LN40A) due to panel heat. Its why they changed to having them at the bottom in the next models. Remove and clean them as well. Clean with a white pencil rubber, rubbing away from the ribbon, never across or towards. Make sure there is no rubber residue to get stuck in the connectors. Some use copper brush for this and then packing to tighten the connectors. Look for electrolysis damage to the ribbon or connector as well (which occurs with water ingress while the panel is powered, unlikely for a top mount tcon). Getting at them requires a bit of disassembly though, leave that to the "clutching at straws" option.

Moving the tcons to the bottom changed faults from design issues to not our fault, user initiated issues. People cleaned the screens with window cleaner sprays and that liquid ran down onto the ribbons and tab pcb.

[saddle_au]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

Sorry I was rambling again. Did that in another post as well today. It's why my workmates called me "Tangent Talker".

[Michale32086]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

It's been my experience that, the cases of TV repair, there is no such thing as TOO MUCH information.

Thanx...

[nomoresonys]

Re: Samsung LN40A500 LCD, Plays Fine For 20m Then Right Side Goes Wanky

its usually only one bad tab bond, I'd carefully tear it down and try to find which one, gentle pressure on each, one at a time, if pic. clears up thats the one.