40" Samsung with White bars, please help!

[TheRoo]

Hey guys, was hoping you guys could tell me what on the board is going out.
I recently replaced the power board thinking it would fix the problem, obviously it didn't

After replacing the power board however, it worked fine for a day or two then yesterday it started with its going white issue. I've taken apart every component and cleaned it, every cable, every connector. I cannot figure out what the issue is, but after some reading on the forums here, the T-CON board seems likely.

Any thoughts/suggestions would be helpful. Video is here. https://youtu.be/YIvVj4rxXI4

Thanks again for your input!

[Alastair E]

Re: 40" Samsung with White bars, please help!

MODEL #?

LCD? Plasma?

No idea whats what without knowing the details !

Pictures of the internal boards will help........

Could be T-Con, Tabs or the LCD Panel.....

[ben7]

Re: 40" Samsung with White bars, please help!

Could be T-Con, Tabs or the LCD Panel.....

Agreed.
I remember someone having an issue with a smaller LCD monitor (eh, maybe it was a TV) that would do something similar. Though, I think it might have been a bad part on the t-con. Don't trust my memory LOL

-Ben

[TheRoo]

Re: 40" Samsung with White bars, please help!

Sorry! Thought I had them in the description.

Model #: LN40B530P7N

It's an LCD screen.

Here's some pictures of the boards.

Also when I powered it on moments ago to see if it gave me the same issue, it did the same thing in the video I posted earlier, but I could of swore I heard a high pitched whistle or buzz coming from the tv.

[ben7]

Re: 40" Samsung with White bars, please help!

Sorry! Thought I had them in the description.

Model #: LN40B530P7N

It's an LCD screen.

Here's some pictures of the boards.

Also when I powered it on moments ago to see if it gave me the same issue, it did the same thing in the video I posted earlier, but I could of swore I heard a high pitched whistle or buzz coming from the tv.

Good pictures!

One thing is certain, when (if) you fix this problem, you should replace the capacitors in that power supply. I see some of those evil Samwha capacitors that are known to fail in Samsung TVs.

I'm not totally an expert at fixing TVs, other than repairing power supplies.
I'll let some of the other folks on here chime in, they will have some good advice as to what to check (and what could be wrong).

-Ben

[vinceroger69]

Re: 40" Samsung with White bars, please help!

Have a read through some of these threads if you havnt already see if any of them have the same problem etc it maybe also worth testing the tcon voltage points and posting in the thread.
https://www.badcaps.net/forum/search...archid=4921335

[TheRoo]

Re: 40" Samsung with White bars, please help!

Have a read through some of these threads if you havnt already see if any of them have the same problem etc it maybe also worth testing the tcon voltage points and posting in the thread.
https://www.badcaps.net/forum/search...archid=4921335

Thanks! After reading all the threads from the link you gave me, definitely sounds like a T-CON board problem. I failed to mention that when the problem started I was feeling around on my TV for heating issue, and quickly realized that the chassis around the T-CON board was very very hot compared to the rest of the TV. Seems like the AS15 chip is bad?

Will post voltages when I figure out how to do them correctly. Thanks!

[vinceroger69]

Re: 40" Samsung with White bars, please help!

post 14 in this thread may help on advice to check gamma voltages
https://www.badcaps.net/forum/showth...ht=LN40B530P7N

[TheRoo]

Re: 40" Samsung with White bars, please help!

**********UPDATE************
Well, trying to list the voltages is useless, as I cannot figure out how to do them correctly. I kept getting small numbers, switched to every setting I could and still had no luck.

After putting the TCON board back in the tv, i powered it up, and heard a solid "buzz" coming from the TCON board. 100% it is the TCON board making the sound as I took about 15 minutes to narrow it down.

However, I do not know why it would be buzzing, it makes me feel like the TCON is bad, but I don't know enough about TV's to make that call. What do you guys think?

[vinceroger69]

Re: 40" Samsung with White bars, please help!

can you upload a picture of the multimeter your using? also has your meter had a new battery in lately.

[TheRoo]

Re: 40" Samsung with White bars, please help!

Sure. Here it is. Fresh batteries put in today.

[vinceroger69]

Re: 40" Samsung with White bars, please help!

So with meter set 20 dc volts black probe on metal part of tv casing or tcon mounting screw tv turned on start testing points in the picture staring from 1 up to 20 i think write down your readings be carfull not too let probe slip as very small test points
a quick check for you meter test a new 1.5 or 9 volt battery just to prove the meters ok and no broken test lead wires etc.

[TheRoo]

Re: 40" Samsung with White bars, please help!

Thank you very much for taking the time to help me with this! I really appreciate it! Here are the readings on the Pins from 1-22, also, I checked and re-checked many times on the pins to make sure I was getting the same readings on them.

1: 15.39
2: 15.39
3: 15.39
4: 15.43
5: 15.45
6: 15.47
7: 15.49
8: 15.49
9: 15.52
10: 15.53
11: 15.54
12: 7.06
13: 6.65
14: 6.51
15: 5.30
16: 4.99
17: 4.34
18: 3.44
19: 2.68
20: 0.66
21: 0.54
22: 0.31

Clearly the first 11 pins are out of whack, getting too much power, what could cause that? Or is it just a bad TCON board?

[vinceroger69]

Re: 40" Samsung with White bars, please help!

yes bad chip on tcon i would recomend changing it ive never done a chip swop myself too be honest.
the start voltage is about right i think it should gradually get less towards test point 22 your is bad around point 11 and 12 try another tcon if i was you try to find someone with a good returns policy as even seconhand one can be faulty too.

[TheRoo]

Re: 40" Samsung with White bars, please help!

Yeah. The only ones I can find are in China from eBay, ShopJimmy doesn't have them anymore.
Part #: AUO 55.40T02.C03
I don't know of any where else to get them. Amazon didn't have any. 60 Day warranty is the best i've been able to find

[vinceroger69]

Re: 40" Samsung with White bars, please help!

maybe other members in the usa can advise shops they use? the chips are cheap but hard to solder from what ive read.

[wills123]

Re: 40" Samsung with White bars, please help!

ive replaced quite a few of the chips,
there not to bad with a hot air setup or rework station, maybe someone in your area can replace the as15 chip for you?
probably be cheaper than a replacment board,

[saddle_au]

Re: 40" Samsung with White bars, please help!

I worry about the buzzing sound you heard. The only times I've heard this coming from the TCON is when a chip on tab in the panel has been destroyed and the TCON is feeding a short circuit. The panel just displays solid white vertical bars later on those tabs when tested in another unit.

AS15 faults normally affect the whole panel, not sections of it, but shorts on the AS15 between pins 8 & 9, 22 & 23, 29 & 30 kill can the panel. I've got two panels like that, a Samsung 26A450 and a 32A450 where someone tried a repair of the TCON but didn't remove all soldering shorts before powerup testing.

AS15 legs and pads are so close they are difficult to manually solder cleanly and visual inspections after are not good enough. Solder wicks up between the legs and can sometimes wick between pads behind the legs. Use lots of flux and run a meter over the chip leg to leg, there should be no pins with adjacent shorts.

[TheRoo]

Re: 40" Samsung with White bars, please help!

The bars are horizontal, but if you look in the video, it starts as a few horizontal bars, then goes the full screen as a bright white, but still able to see everything on the screen. The TCON has to be bad with those voltage tests right?

[saddle_au]

Re: 40" Samsung with White bars, please help!

Horizontal bars can also be TCON timing issues. And yes the voltages look bad.

I'd have a go at the TCON or get a replacement (even temporarily). Get some AS15 chips and find someone to swap them for you. Go see your local college (uni or whatever you call them) and find the electronics geeks who work there, I'm sure they like beer.

The bottom pad may or may not be soldered, easier removal if not. I've done 3 AS15s today and only one of them had solder on the base pad. It doesn't seem to have helped though, it still died.