SAMSUNG LA40A656 with vertical lines at startup

[v0ltair3]

Hi Everyone,

I've just come across with this amazing site while trying to troubleshoot a recent problem that's happening with my TV set.

From 2 days ago, whenever I turn on my TV I can't see a clear image, rather I see that the image is basically transformed into a bunch of vertical lines like below:



Now if I try to loop the different sources for a few seconds (say 10 seconds), i.e. try to loop between the analog and digital sources, I eventually see a "normal screen" and its stays like that for as long as the TV is turn on, literally hours... this problem only happens again If I turn the TV off, wait a bit and then turn it on again.

The only problem I see when I do this is that the image has some kind of "drag effect" in some type of images, like presenting the menu.




I saw already some people complaining about this issue but I never saw the outcome... from what I've read in this forum already it seems to be related to the TCON board, but I was counting with the experience of the badcaps JEDIs to help me figure it out.

Thanks a ton in advance for any guidance you might provide me.

[Diah]

Re: SAMSUNG LA40A656 with vertical lines at startup

turn it off, and then on.to show this fault. don't play or touch any on TV or RC. leave it and calculate the time how long it will show normal after turning it on. don't touch any let see if it come back alone or not.. so give time to it

[Moreno83]

Re: SAMSUNG LA40A656 with vertical lines at startup

This is either a tabbonding issue on the panel or bad t-con. I hope its t-con....

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

turn it off, and then on.to show this fault. don't play or touch any on TV or RC. leave it and calculate the time how long it will show normal after turning it on. don't touch any let see if it come back alone or not.. so give time to it

Hi Diah,

first of all, thanks for the support, this is actually a nice angle..

Indeed the TV "recovered" by it self after about 10 seconds... I was wondering it was related to the swap of the different sources but its apparently irrelevant.

Does it somehow helps with the root cause analysis ?

Thanks

[Diah]

Re: SAMSUNG LA40A656 with vertical lines at startup

its time now to open the cover and clean & reseat all cable and LVDS from MB to T-CON also the ribbon cable from T-CON to panel.. be cartful that LVDS and ribbon cable may dry out, and silver or gold pin are easily break from the its pad

also do Factory reset . at this stage hope it will be normal.. if not then report here to go further electronic test - messurment

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

This is either a tabbonding issue on the panel or bad t-con. I hope its t-con....

If it's down to the panel it will be game over lets hope its not...

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

its time now to open the cover and clean & reseat all cable and LVDS from MB to T-CON also the ribbon cable from T-CON to panel.. be cartful that LVDS and ribbon cable may dry out, and silver or gold pin are easily break from the its pad

also do Factory reset . at this stage hope it will be normal.. if not then report here to go further electronic test - messurment

Will do it in a few hours and revert back on this thread regardless of the outcome so other can take something out of it as well

Thank you

[cliff_hootarski]

Re: SAMSUNG LA40A656 with vertical lines at startup

Since this is a Samsung "A" model, could this be caused by a "C102" issue?

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

its time now to open the cover and clean & reseat all cable and LVDS from MB to T-CON also the ribbon cable from T-CON to panel.. be cartful that LVDS and ribbon cable may dry out, and silver or gold pin are easily break from the its pad

also do Factory reset . at this stage hope it will be normal.. if not then report here to go further electronic test - messurment

I've made a cleanup of PSU, MB & T-CON board as well as reseat all cables including LVDS & ribbons that go out of the T-CON + factory reset, but the problem persists

After some time of the startup the TV goes "normal" as stated above and stays like that for hours to come until the next time turn off & on. (this time took almost a minute, but when "cold" it usually take a bit longer)

Below some pictures of the power supply & main board. I see at least one cap that needs replacement on the PSU and a weird liquid form stuff in the back of the MB (PCB Varnish ??).

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

Since this is a Samsung "A" model, could this be caused by a "C102" issue?

H Cliff,

I am not aware of this C102 problem, can you kindly elaborate a bit more ?

Thank you

[cliff_hootarski]

Re: SAMSUNG LA40A656 with vertical lines at startup

A lot of the "A" model Samsungs both plasma and LCDs have a well known problem of a certain capacitor C102 on the back side of the main board which causes all kinds of problems. However, I do not see this cap on your board.

[Diah]

Re: SAMSUNG LA40A656 with vertical lines at startup

the MB look had allot of dioxide, you need to use ethanol to clean it.

you need to narrow now which board make this noise at first start ( Cold state ) , use hair dryer to really warm up boards one by one then start the TV, to see which one will let it start normal. begin with MB.

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

the MB look had allot of dioxide, you need to use ethanol to clean it.

you need to narrow now which board make this noise at first start ( Cold state ) , use hair dryer to really warm up boards one by one then start the TV, to see which one will let it start normal. begin with MB.

I've mande a run on all 3 boards, PSU, MB and TCON.. at a first run it wasn't really deterministic, but I've then focus on the TCON and I was trying to turning off and on with or without heating the board to understand if there were some cause effect.

After a 3 or 4 runs were I was basically under the 20 seconds to a full working TV, it kind of get always OK and now startups correctly immediately. I've give it a good couple of hours of viewing and it was basically OK (it stopped working for a few seconds and the back to normal)

So I would say its around the TCON board, so it seems for now.

Is there any chance that the problem could be related with the ribbons that go towards panel itself ?

Thank everyone and wishing you all a happy new year!

[diif]

Re: SAMSUNG LA40A656 with vertical lines at startup

Have you changed the bulging cap on the power supply ?

[ReeceyBurger123]

Re: SAMSUNG LA40A656 with vertical lines at startup

Jeez,wait for Ali E to chime in he will know thr exact issue but might be a bit pissed you've not researched this chassis. Im busy today so will reply in a few days if he doesn't.

[Diah]

Re: SAMSUNG LA40A656 with vertical lines at startup

I've mande a run on all 3 boards, PSU, MB and TCON.. at a first run it wasn't really deterministic, but I've then focus on the TCON and I was trying to turning off and on with or without heating the board to understand if there were some cause effect.

After a 3 or 4 runs were I was basically under the 20 seconds to a full working TV, it kind of get always OK and now startups correctly immediately. I've give it a good couple of hours of viewing and it was basically OK (it stopped working for a few seconds and the back to normal)

So I would say its around the TCON board, so it seems for now.

Is there any chance that the problem could be related with the ribbons that go towards panel itself ?

Thank everyone and wishing you all a happy new year!

change this cap as marked on the photo attached..

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

Jeez,wait for Ali E to chime in he will know thr exact issue but might be a bit pissed you've not researched this chassis. Im busy today so will reply in a few days if he doesn't.

Hi ReeceyBurger123,

not my intension to piss off anyone but I didn't really found this exact problem, nevertheless I understand I will likely not be the first one with this issue

I've try to do my homework and I did found a similar problem but the thread was missing the resolution...

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

change this cap as marked on the photo attached..

Hi Diah,

I did change that cap already (it's a 470uF) but the problem is still there... I did another round heating the the T-CON and it started immediately so I'm almost sure the problem is focused there.

I've noticed that some of the ribbon contacts are starting to peel off, I've position them carefully and it's now ok again but will eventually need to replace them as well.

Below some closeups on the T-CON in case it help..








Thank you

[v0ltair3]

Re: SAMSUNG LA40A656 with vertical lines at startup

Did anyone experience a similar problem ? I would purchase a new t-con board if I would be sure it's not planned related..

Thank you