Samsung LN-S4095D Garbled Display on all Inputs

[musjim]

This LCD will show a clear screen on the menus and when no signal is being sent, clear blue screen. When on any input the picture is all garbled. I think it may be something with the main board but not sure if it could be caps? All of them are the SMD type on the board. I haven't started testing yet, and there are no replacements in the wild, so I'm stuck trying to figure this one out.

[PlainBill]

Re: Samsung LN-S4095D Garbled Display on all Inputs

You have already indicated the area of the problem, you just don't have the experience to recognize it.

The menus and the blue screen are generated in the graphics processing chips. They are working properly, therefor the problem lies upstream from that - the signal input circuitry. Before waiting for someone to put a Wii nunchuk through the screen of their LN-S4059, I'd first of all check ALL inputs - tuner, HDMI, component, and composite. Then I'd start looking at the LDO regulators on the main board. The problem is consistent with a bad one (noisy or wrong output voltage).

PlainBill

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Great, that puts me in the right direction. I've confirmed the garbled screen on all inputs (tuner, HDMI, component, and composite), so off to tracing down the voltages. Just pulled down the service manual from Elektro Tanya. Thanks.

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Ok, I need some help with tracing the circuit. The manual has a schematic, but I think its a little different from the board I have. I can not seem to find a couple of the LDO's to confirm voltages. I've attached a couple pics of the four I recognize. Here are two that are suspect to me.

IC151 - AC 17-33 06425L
Tab- 3.31
Pin1- .002
Pin2- x (no pin)
Pin3- 0.0L

IC111 - KIA 78005F 643
Tab- .002
Pin1- 0.0L
Pin2- x (no pin)
Pin3- 0.0L

[PlainBill]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Ok, I need some help with tracing the circuit. The manual has a schematic, but I think its a little different from the board I have. I can not seem to find a couple of the LDO's to confirm voltages. I've attached a couple pics of the four I recognize. Here are two that are suspect to me.

IC151 - AC 17-33 06425L
Tab- 3.31
Pin1- .002
Pin2- x (no pin)
Pin3- 0.0L

IC111 - KIA 78005F 643
Tab- .002
Pin1- 0.0L
Pin2- x (no pin)
Pin3- 0.0L

Set your DMM to the next higher range. What you are reporting as 0.0L is 'OL', meaning 'Over range'.

PlainBill

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Set your DMM to the next higher range. What you are reporting as 0.0L is 'OL', meaning 'Over range'.

PlainBill

That helps. Updated readings. These were taken while the screen was on with cable input.

IC151 - AC 17-33 06425L
Tab- 3.31
Pin1- .002
Pin2- x (no pin)
Pin3- 5.0

IC111 - KIA 78005F 643
Tab- .002
Pin1- 9.02
Pin2- x (no pin)
Pin3- 5.00

[PlainBill]

Re: Samsung LN-S4095D Garbled Display on all Inputs

That helps. Updated readings. These were taken while the screen was on with cable input.

IC151 - AC 17-33 06425L
Tab- 3.31
Pin1- .002
Pin2- x (no pin)
Pin3- 5.0

IC111 - KIA 78005F 643
Tab- .002
Pin1- 9.02
Pin2- x (no pin)
Pin3- 5.00

Those look good. The first is a 1700 series 3.3V LDO regulator, the second is a variant of the familiar 7800 series regulators.

PlainBill

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Those look good. The first is a 1700 series 3.3V LDO regulator, the second is a variant of the familiar 7800 series regulators.

PlainBill

Found some more,first two on front, rest on back of the board.

IC061 - M 39300 2.5WU 0630
Tab- 0.0
Pin1- 3.35
Pin2- x (no pin)
Pin3- 2.49

IC015 - 2.5 SC156651M 0638 G0613109-1
Tab- 0.0
Pin1- 3.37
Pin2- 3.37
Pin3- 0.0
Pin4- 0.0
Pin5- 2.5

IC184 - 78M09A GB 98
Tab- 0.0
Pin1- 13.10
Pin2- x (no pin)
Pin3- 9.05

IC188 - 269-5G RF641 ON
Tab- 4.9
Pin1- .01
Pin2- x (no pin)
Pin3- 6.0

IC063 - AC 17-18 06421L
Tab- 1.82
Pin1- 0.00
Pin2- x (no pin)
Pin3- 3.39

IC112 - BA033 6A 46
Tab- 0.0
Pin1- 5.43
Pin2- x (no pin)
Pin3- 3.39

IC104 - AC 17-25 06381L
Tab- 2.52
Pin1- 0.0
Pin2- x (no pin)
Pin3- 5.42

IC187 - 78M08A GB 1B
Tab- 0
Pin1- 13.0
Pin2- x (no pin)
Pin3- 7.85

IC094 - AC 17-25 06381L
Tab- 2.52
Pin1- 0.0
Pin2- x (no pin)
Pin3- 5.49

[PlainBill]

Re: Samsung LN-S4095D Garbled Display on all Inputs

The only ones that look unusual are IC187 - should be 8.0, is 7.85 and IC112 - should be 3.30, is 3.39. Normally these are accurate to within 1%, these are about 2%. Still, the outputs are within the nominal input tolerance of the ICs they supply.

I don't see any readings that indicate anything should be replaced.

PlainBill

[Village Electronics]

Re: Samsung LN-S4095D Garbled Display on all Inputs

This LCD will show a clear screen on the menus and when no signal is being sent, clear blue screen. When on any input the picture is all garbled. I think it may be something with the main board but not sure if it could be caps? All of them are the SMD type on the board. I haven't started testing yet, and there are no replacements in the wild, so I'm stuck trying to figure this one out.

How about a picture of "garbled"? And a "good menu"?

I know that you don't want to hear this but I have seen that symptom more than once on various brands and I can't explain why it happens the way it does.
It was in the cases that I personally saw a bad panel.

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

How about a picture of "garbled"? And a "good menu"?

I know that you don't want to hear this but I have seen that symptom more than once on various brands and I can't explain why it happens the way it does.
It was in the cases that I personally saw a bad panel.

Yeah, not the news I want to hear. But I'll keep tinkering with the board to see if I can trace anything else unusual. Might invest in another board if can find one cheap to validate. Then it will be on to selling off the parts. Thanks.

[musjim]

Re: Samsung LN-S4095D Garbled Display on all Inputs

The only ones that look unusual are IC187 - should be 8.0, is 7.85 and IC112 - should be 3.30, is 3.39. Normally these are accurate to within 1%, these are about 2%. Still, the outputs are within the nominal input tolerance of the ICs they supply.

I don't see any readings that indicate anything should be replaced.

PlainBill

Bit the bullet and replaced the main board. Found one pretty cheap, so I sunk the $65 bucks for a used board. Popped it in and fixed it. Updated firmware to latest version and now have a great 1080p 40" Samsung for under $200. Next victim is the Sharp Aquos. Thanks guys.

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Hey guys, I hate to resurrect an old thread, but this is the same issue that I have with my TV. And I know this is an old thread, and an old TV, but since it's such a good model, if I can save it for relatively inexpensively, that's the plan.

The caveats, I've done some electronics projects so am comfortable around meters (with some direction), soldering, components, etc... But not real hands on experience reading schematics or anything like that.

I've found and downloaded what was labeled as the repair manual, but it's only the chapter on schematics, and none of the other troubleshooting chapters. I have also not had much luck finding the full troubleshooting manual either (I'm guessing the age of the TV has something to do with that).

So I can start looking at the LDOs on the main board, but when I read the pins, where do I attach my meter's ground probe? Do I just clip it to a screw or the chassis? Also, when starting my measurements, do I disconnect anything or does it all stay connected?

Any other hints, tips or caveats that I should be aware of as I check these components?

[jetadm123]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Connect ground lead to chassis. Screw can also be used as they are usually screwed into the chassis. Leave everything connected while you take voltage measurements of each LDO.

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Thanks for the tip. One question, where are you getting the information to verify these LDO components? Are you looking in a component spec guide, or at the tv specs and schematics?

My readings are

Front
IC151 - AC 17-33 06381L
Tab- 3.28
Pin1- .001
Pin2- x (no pin)
Pin3- 4.97

IC111 - KIA 78D05F 639
Tab- .001
Pin1- 8.9
Pin2- x (no pin)
Pin3- 5.09

IC061 - M 39300 2.5WU 0629
Tab- 0.0
Pin1- 3.32
Pin2- 0.0
Pin3- 2.48

IC015 - 2.5 SC156615M 0637 G0611734-1
Tab- 0.0
Pin1- 3.29
Pin2- 3.29
Pin3- 0.0
Pin4- 0.0
Pin5- 2.47

~~~~~~~~~~~~~~~~~
Back

IC184 - 78M09A GA 2B
Tab- 0.0
Pin1- 12.93
Pin2- x (no pin)
Pin3- 8.92

IC188 - 269-5G RE632
Tab- 4.98
Pin1- 0.00
Pin2- x (no pin)
Pin3- 5.94

IC063 - AC 17-18 06383L
Tab- 1.802
Pin1- 0.00
Pin2- x (no pin)
Pin3- 3.31

IC112 - BA033 68 94
Tab- 0.0
Pin1- 5.38
Pin2- x (no pin)
Pin3- 3.33

IC104 - AC 17-25 06386L
Tab- 2.50
Pin1- 0.0
Pin2- x (no pin)
Pin3- 5.37

IC187 - 78M08A GB 1B
Tab- 0
Pin1- 13.03
Pin2- x (no pin)
Pin3- 7.99

IC094 - AC 17-25 06386L
Tab- 2.49
Pin1- 0.0
Pin2- x (no pin)
Pin3- 5.39

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

I did find some other smaller voltage regulators on both the front and back, should I be measuring those as well? Or is it typically the LDO regulators that are suspect?

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Ok, I picked up a main board and replaced it, and the primary issue is resolved. But there is still little static-type of dots on the screen (a different type of dot, much smaller). Not over the entire screen, just in various parts. When the TV has been off for a while, (overnight) then first turned on, it's a good clean picture. Gradually, starting at the left, the dots will appear and they seem to almost scroll down the screen (like the matrix screen saver). Not bad at first, just little speckles here and there. But gradually, over the next few minutes to hour, it will get worse, the dots get more frequent and not larger, but just more of them, and gradually cover the screen. It's not a full coverage though, just enough to be annoying, almost like an analog TV that is not tuned in.

I have verified consistent dot patterns on HDMI 1 & 2 and the Component inputs.

Is this still a main board issue (the board that I got is bad)? Or something else (i.e. power supply board)?

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Back to looking at this issue again and looking for some assistance. What do I start looking at to troubleshoot? The dots start to appear after the TV is on for ten to fifteen minutes, and gradually get worse. They don't seem to cover the entire screen, just concentrated more or less in vertical strips (see attached image). Is the main board that I replaced also bad? Or am I looking at something else that is the problem?

[osh]

Re: Samsung LN-S4095D Garbled Display on all Inputs

Anyone? Help? Can someone offer some direction on what to look at next?

[CapLeaker]

Re: Samsung LN-S4095D Garbled Display on all Inputs

flex the screen a little on the top