Samsung LCD LN40A500T1F solarized then black screen

[tsm174]

My TV is a solid black (but lit) screen, all inputs, all the time.

I picked up this TV yesterday from someone that said "the colors are all messed up". The picture was really badly solarized. I found a youtube video which referenced a service menu option called DDR but I never found that option in the service menu. Tried a factory reset and no change (still solarized). Then, I unplugged the cables connecting to the tcon board and cleaned them with contact cleaner and replaced them. When I replaced the two cables at the top of the board, I didn't have one in quite all the way. The screen started turning completely white, then I got some smoke from the card, and I think the foam pad on the back of the biggest chip slid down (like the adhesive melted or something). I think I unplugged and re-plugged those two cables again, and now the display is completely black.

So, my best guess is that I've fried something on the tcon board but I don't want to throw $50 at it without knowing if there's any hope for the success. Can anyone help me do a bit more diagnostics?

I'll try to add a pic here in a minute.

[Hamie]

Re: Samsung LCD LN40A500T1F solarized then black screen

Well it going to be difficult to trouble shoot now the tcon is damaged.
The tcon might have been faulty in the first place but because it's definitely damaged you now won't be able to tell if it was working before hand because all the test points on tcon will now be irrelivant.

Furthermore not having the ribbon cables in place properly can blow the panel ICs.

I'm afraid you'll need to either take the risk of a new tcon and hope the panel is ok.

[newtothis]

Re: Samsung LCD LN40A500T1F solarized then black screen

Solarized... Bet its an AS15 tcon.

Can you give us a really detailed picture of the tcon please?

If it is indeed an AS15 tcon then that would of been the cause of the initial fault. You could replace the tcon which would of sorted out the initial problem but you will be hoping you didn't cause any further damage. I have misaligned ribbons before and smoked an AS15 as you probably have and did not damage anything else.

[tsm174]

Re: Samsung LCD LN40A500T1F solarized then black screen

Here's the best pic I have at the moment.

[newtothis]

Re: Samsung LCD LN40A500T1F solarized then black screen

That's good enough for me to tell you the Gamma IC was faulty on your tcon which led to the solarized colours.

Could of changed the Gamma IC on its own (Little fiddly especially if not got a lot of soldering experience with fine pitch) but as you smoked the board I would just replace it. Chances are you won't have damaged anything else.

Good Luck

[budm]

Re: Samsung LCD LN40A500T1F solarized then black screen

I just hope that the ICs in the panels are not damaged.

http://www.shopjimmy.com/cmo-35-d026047-t-con-board.htm
It uses AS19.

More likely the switching power supplies are damaged.

[tsm174]

Re: Samsung LCD LN40A500T1F solarized then black screen

Thanks for your input. So I can learn a little bit here, can you explain what you're seeing that tells you the Gamma IC was faulty?

Looks like I'll be getting a new tcon and crossing my fingers.

[tsm174]

Re: Samsung LCD LN40A500T1F solarized then black screen

More likely the switching power supplies are damaged.

Any way to test this before I order a new tcon?

[tsm174]

Re: Samsung LCD LN40A500T1F solarized then black screen

I went ahead an got a new tcon, going to install it tonight. Anything I should be looking at before installing the new tcon?

[newtothis]

Re: Samsung LCD LN40A500T1F solarized then black screen

Hey sorry for not answering previously.

As far as knowing it was the Gamma IC... Experience of seeing it plenty of times before and repairing Tcons.

Just make sure you get the cables in right this time and make sure they are clean of any carbon from shorting before. All you can do is plug it in and hope!

[tsm174]

Re: Samsung LCD LN40A500T1F solarized then black screen

Popped in the new tcon and good as new! Thanks all.

[newtothis]

Re: Samsung LCD LN40A500T1F solarized then black screen

Popped in the new tcon and good as new! Thanks all.

Awesome news!

Thanks for the follow up