How do I test TCON?

[primetime]

I am not a pro. I am working on a Samsung UN46B6000FUZA LCD television that the previous owner spilled liquid on and continued to use which lead to the corrosion of the traces and capacitors on the board attached to the panel. Initially, the problem was there were vertical, multicolored bands, about five inches wide on the right side of the screen and the picture would black-out every second and come back on and so on. The image underneath the bands looked OK otherwise. When I saw the corrosion and the sticky liquid covering the board I immediately cleaned it off with some alcohol. A few of the traces lifted right off and a few of the capacitor ends were corroded.





When I turned the TV on again, the multicolored band was gone and the picture stayed on except it was now washed-out white and negative with slight flickering. Sound is OK. I do not think the flickering is from the backlight.



I reconnected the broken traces with bridge wires and reflowed solder on the capacitors. After all that work the problem persisted as if I didn't do a thing.



I then tried a different TCON board, but the replacement was defective on arrival due to several capacitors being knocked off, probably due to poor storage. I was able to replace the capacitors and got the TCON working, or so I thought, but the problem persisted. What are the chances the replacement TCON would have the same problem as the original I asked myself. Is the TCON even the problem I asked myself again. So I replaced the video board and the problem persisted with either TCON boards. I noticed there are two different writings on the tuner shield: one green and one red. I wonder if someone tried to repair this before I got a hold of it. The other boards I have seen only had the green OK color.




I checked the voltages from the power supply going to the video board. They appear to be OK. Although, pins 19 and 21 which are labeled 12V actually measured 12.8 volts.




So, I'm at a deadlock at this point. I'm not ready to give up on this TV yet. I need help on how to test the TCON. Can anyone provide the service manual for this TV or the TCON?

It could be the panel board with the corrosion still has a short some place or perhaps the panel is toast or the replacement TCON was defective.

[budm]

Re: How do I test TCON?

Pictures of the T-CON board? You should also test the voltages at the GAMMA Voltage test points on the T-CON board.

[primetime]

Re: How do I test TCON?

I uploaded the TCON picture. Is the TCON picture not showing for you or not high resolution enough?

I didn't see the gamma on the TCON but there is gamma on the two board strips attached to the panel. Is that what you are referring to? I don't know what voltages to reference on that gamma?

[budm]

Re: How do I test TCON?

I could not see clear enough the white text on the T-CON board to locate the GAMMA Voltage test points, usually around 15~20 test points.

[budm]

Re: How do I test TCON?

OK, I found good picture on the SJ site, but I do not see the test points for GAMMA Voltages.
http://www.shopjimmy.com/media/catal...j35d044455.jpg
But you found them on the tab boding board, so use the DCV meter black probe on the chassis, red probe on each test point and report them in sequence.
1 = xxx V
....
20 = xxx V

[primetime]

Re: How do I test TCON?

Test points 18, 19, 20 fluctuate rapidly up and down in the range indicated. The other test points are steady. The results are mirrored on the other board as well.

1 = 16.86 volts
2 = 15.93
3 = 13.78
4 = 12.89
5 = 11.89
6 = 11.51
7 = 11.27
8 = 10.91
9 = 10.37
10 = 9.47
11 = 7.81
12 = 7.09
13 = 6.47
14 = 6
15 = 5.72
16 = 5.35
17 = 4.34
18 = 3.39-3.43
19 = 1.2-3.2
20 = 0.2-3

[Seanyc]

Re: How do I test TCON?

Hi can any 1 help me also sorri if posted in wrong part new to forums
I have a Samsung LE32c450e1w
And it developed red lines down the screen this only happens when the to get worm then they start to fad and the come back is there a fix for this please
I've had a look at the insides of the tv and can't see any broken or damage
Cheers seamy

[tom66]

Re: How do I test TCON?

The gamma voltages look good to me.

@Seanyc please start your own thread

[primetime]

Re: How do I test TCON?

Voltages on test points 18, 19 and 20 fluctuate five times a second. Is that still normal?