Samsung LNS3241D - No picture, sound and backlight OK

[Kristofor]

Four year old LCD TV first started showing problems with intermittent vertical lines across the entire screen; of varying number, width, and color. Now it turns on and stays on, but there is no picture, not even for a second; does not matter what source. Even the menu items do not display. The audio is fine and the backlight is on.

I replaced a bulging 470uF, 25V cap.
24VDC checked going to the inverter board.
5.4, 12, and 13VDC look good going to the main board.
LVDS cable and end connections appear okay. Contacts cleaned.
Fuse F1 on the Tcon board is good.

Is there any thing else, fairly easy to check, to narrow down the problem? I do have access to an O-scope from work, but do not have a lot of money to throw around. Any help would be greatly appreciated.

[PlainBill]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Four year old LCD TV first started showing problems with intermittent vertical lines across the entire screen; of varying number, width, and color. Now it turns on and stays on, but there is no picture, not even for a second; does not matter what source. Even the menu items do not display. The audio is fine and the backlight is on.

I replaced a bulging 470uF, 25V cap.
24VDC checked going to the inverter board.
5.4, 12, and 13VDC look good going to the main board.
LVDS cable and end connections appear okay. Contacts cleaned.
Fuse F1 on the Tcon board is good.

Is there any thing else, fairly easy to check, to narrow down the problem? I do have access to an O-scope from work, but do not have a lot of money to throw around. Any help would be greatly appreciated.

The symptoms indicate a bad tcon. The intermittent vertical lines across the full screen indicate it's not a bad panel.

PlainBill

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Fixed Samsung T-cons before, the fuse often blows, but the board is cheap anyway. You problem doesn't really sound like a fuse though.

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Thank You Bill.

I did not know how to isolate the problem between the main board and Tcon. Is there a preferred place to purchase the Tcon board? Any places i should stay away from? Should i get the cable too?

If it makes a difference, I did measure a few voltages on the LVDS connector on the main board side (ones that i could get to). All measured referenced to frame ground, VDC:

AO1; 1.159
A1-; 1.186
GND; 0
A2+; 1.235
CLK-; 1.156
GND; 0
A3+; 1.167
NC; 0
NC; 0
GND; 0
PANEL_V; 5.36
PANEL_V; 5.36
PANEL_V; 5.36

Thanks again.

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Thank You Bill.

I did not know how to isolate the problem between the main board and Tcon. Is there a preferred place to purchase the Tcon board? Any places i should stay away from? Should i get the cable too?

If it makes a difference, I did measure a few voltages on the LVDS connector on the main board side (ones that i could get to). All measured referenced to frame ground, VDC:

AO1; 1.159
A1-; 1.186
GND; 0
A2+; 1.235
CLK-; 1.156
GND; 0
A3+; 1.167
NC; 0
NC; 0
GND; 0
PANEL_V; 5.36
PANEL_V; 5.36
PANEL_V; 5.36

Thanks again.

Can you take a picture of the T-con and post it here?

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Thanks Tom, Attached is a pic of the Tcon board...

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I see one fuse, F1, on the board, to the right of the connector. Can you test that fuse?

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I did measure F1 Tom. Resistance is near zero with the power off. I measure 5VDC on both sides with power on. Thanks for the feedback.

It may be interesting to note that the TV behaves exactly the same with the LVDS cable (I believe that is the cable to the T-con from the main board) connected or not.

Please keep the suggestions coming...

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

On the righthand side, L33V. What voltage does that measure at?#

Since you are getting some voltages on the LVDS, I'm very tempted to say T-con.

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Thanks, I'll check out L33V when i get home.

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I just can not find an L33 anywhere. There are several V33's indicated and each measures 3.3VDC.

I did notice a POW_ON label near RP27 with a solder connection that i could probe. It only measures 0.005VDC. It is located just above the LVDS cable, above and to the left of F1. Any ideas that this is normal?

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I just can not find an L33 anywhere. There are several V33's indicated and each measures 3.3VDC.

I did notice a POW_ON label near RP27 with a solder connection that i could probe. It only measures 0.005VDC. It is located just above the LVDS cable, above and to the left of F1. Any ideas that this is normal?

My error. I meant V33.

I'm drawing blanks. I say just replace the T-con and see if that fixes it.

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Thank you for your assistance Tom. I do have one more observation and another question to make sure the problem is not with the main board.

In an earlier post i listed voltages from the LVDS cable with all cables connected. Last night i unplugged the LVDS cable on the main board to gain access to the rest of the pins on that cable, this is what i measured:

GND; -0.001
A1+; 1.028
A2-; 0.795
GND; 0
CLK+; 1.308
A3-; 1.220-1.226
GND; 0
PANEL_V; 3.528
GND; 0
GND; 0
PANEL_V; 5.37
PANEL_V; 5.37

Notice that one PANEL-V is lower than the other five. Could this be the problem or is this normal?

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

If the V33 point measures the same as that odd PANEL_V voltage, I'd say it's fine.

[Harvass]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I just wanted to let you know that i have been following this thread with the same problem and i went ahead and bought a used t-con board and it fixed my problem.So i can say that i'm 99% sure a t-con board will fix your problem.

[Kristofor]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Yep, it was the T-con board. Replaced it and all is well again. Thanks everyone for the help.

[kammerer1]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Hi guys,
I have the same problem with the exact same model Samsung. Just wondering where you purchased new (or used) t-con board, price, and see if everything was still working. Much appreciate any suggestions! Thanks

[tom66]

Re: Samsung LNS3241D - No picture, sound and backlight OK

Hi guys,
I have the same problem with the exact same model Samsung. Just wondering where you purchased new (or used) t-con board, price, and see if everything was still working. Much appreciate any suggestions! Thanks

eBay is a good source for boards.

[dcapper]

Re: Samsung LNS3241D - No picture, sound and backlight OK

I'm having a similar problem and I was wondering if any of you can check out the thread I started and give me some advise. It would be appreciated.

https://www.badcaps.net/forum/showth...d=1#post401162

[davi0220]

Re: Samsung LNS3241D - No picture, sound and backlight OK

would TCON solve this problem I'm having same problem (no picture has sound) I recently ordered the caps (equivalent) installed them since i've noticed 2 were bulged and decided replace them all from clean slate...it was great for good 10 mins...until it came back how it was no picture and but sound with lines on the screen as illustrated on my pic..