Samsung LN40A530P

[thecynic0]

I am trying to troubleshoot a Samsung LN40A530P1FXZA that displays bad coloring. I attached a couple of photos taken with a phone. I am wondering if this is due to a bad TCON, Mainboard or LCD screen. By the way this is a great board, some of the threads, especially the best dumpster finds, are hilarious. Thanks!

[tom66]

Re: Samsung LN40A530P

I just fixed one like this, 37" Sony but I'll bet it's the same fault, gamma IC failure. Post a picture of your T-con. You will need some decent soldering skills to replace the IC or you can replace the T-con outright or get it repaired by a repair service company.

[budm]

Re: Samsung LN40A530P

if this is the T-CON board used in his TV, then it is proably another failed AS15 GAMMA IC.
http://www.shopjimmy.com/media/catal...5507a9q001.jpg

[tom66]

Re: Samsung LN40A530P

Well, I do see an AS15 on that board.
Blimey, this is a huge issue. It seems to have gotten a lot worse recently.

[thecynic0]

Re: Samsung LN40A530P

Thanks guys.

I wanted to take a picture of the TCON board but the plate on top appears stuck to the board! Here's a couple of photos.

Solder or whatever else they use on the board, must somehow melted and glued the board to the plate. What do you think?

[tom66]

Re: Samsung LN40A530P

There are thermal pads under there which use a light glue. Remove the board from the TV and apply firm, but gentle pressure to the edges of the board to separate it from the thermal pads.

[thecynic0]

Re: Samsung LN40A530P

Thanks Tom.

Here's a snap of the TCON board.

[tom66]

Re: Samsung LN40A530P

Top of the board - See the box marked GAMMA...

You need to install the board in the TV and connect it up. Screw the board down, but leave the metal shield off for now. Power up the TV so yuou can see the fault on the screen. Use a digital multimeter to check each GAMMA voltage. Report each voltage for each gamma number.

Use the red probe on the test point, place the black probe on the TV's chassis, and use the DC 20V scale (if your meter autoranges just use DC volts; most cheaper multimeters do not autorange.)

[thecynic0]

Re: Samsung LN40A530P

I did not have a multimeter handy and had to get one from work. I got the following V readings:

1 15.04
2 12.87
3 0.02
4 11.21
5 10.92
6 10.84
7 11.82
8 0
9 14.14
10 8.22
11 11.19
12 6.25
13 5.22
14 4.78
15 4.39
16 3.45
17 2.61

DRL1 3.28
DE1 0.78
STV 0
CKV 1.82
VSCW 6.80

v11 of your spreadsheet gives the attached gamma plot.

[tom66]

Re: Samsung LN40A530P

Yep, that is a bad gamma IC. You posted within about 5 minutes of the other guy who also had a bad gamma IC. Replace the IC marked AS15, or replace the T-con board.

[thecynic0]

Re: Samsung LN40A530P

Tom, many thanks!

I am a programmer by profession but this is fun.

[tom66]

Re: Samsung LN40A530P

I also program and design electronic systems. C, Python and Perl mainly. TV repair is just a hobby.

[thecynic0]

Re: Samsung LN40A530P

Nice, if you ever travel my way to San Diego, it'd be my pleasure to invite you for drinks or dinner.

[thecynic0]

Re: Samsung LN40A530P

I replaced the old TCON board with a new one I got off of ebay. Attached is photo with the new board. The picture quality has definitely improved. The TV is almost OK on a high brightness(80/100), lower contrast(75/100) setting.

[tom66]

Re: Samsung LN40A530P

Repeat the gamma voltage test. If the voltages are still bad you received a bad board (which seems very common as sellers don't test their boards. These boards have about a 10,000 hour lifespan.)

[thecynic0]

Re: Samsung LN40A530P

The readings with the new TCON are monotonically decreasing:

Volt 1 13.96
Volt 2 11.21
Volt 3 10.57
Volt 4 9.77
Volt 5 9.56
Volt 6 9.27
Volt 7 8.85
Volt 8 7.78
Volt 9 7.02
Volt 10 6.47
Volt 11 6.07
Volt 12 4.8
Volt 13 4.3
Volt 14 4.02
Volt 15 3.68
Volt 16 2.89
Volt 17 2.2

Here's the gamma check excel with the values entered.

[tom66]

Re: Samsung LN40A530P

They are still bad. Volt 1 should start at 15V and Volt 2 should be closer to Volt 1 than it is. Also, the curve is not symmetric. The spreadsheet can't detect all faults.
I think I'm going to write a web tool for doing gamma tests now the problems are getting a lot more varied. Spreadsheet math is hard.

[Netcatpr]

Re: Samsung LN40A530P

HI thecynic0 and tom66
I'm really shocked that we both have the same problem and same tcon board(v400H1-C03). I also buy a replacement on the internet with exactly the same results (the tv improve the image but not totally).I did the test and these are the results

oem replacement
1 14.9 15
2 12.7 12.9
3 11.8 12.1
4 10.3 11.2
5 8.7 10.8
6 9.8 10.4
7 10.6 10
8 9.2 9.3
9 8 8.8
10 6.8 6.4
11 6.2 6.2
12 5.5 5.4
13 5 4.9
14 4.7 4.5
15 4.3 4.1
16 3.4 3.2
17 2.6 2.4
The new replacement seems to be bad, I already ordered a new tcon from other source, I let you knows if this resolve the issue.

[Netcatpr]

Re: Samsung LN40A530P

there are the pics of the tv with the original Tcon and the graphic with the volt tests.

[SlickClick]

Re: Samsung LN40A530P

Interesting I had a smasung 32 inch that had this issue and it turned out to be a mainboard and the t-con... but i still have the old t-con... i am curious to know the specs and variances in voltage range as it begins to fail... because the t-con i have works great for about an hour and then begins to slide off into hippytrippy land...

on a side note what i began to do now is throw out the metal shield -it retains heat- add a small heatsink to the t-con processor and add a 12v fan to the case... I also add heat sinks to the HDMI processor chips on the mobo and main cpu(s)