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Samsung Flat Panel Blank Screen (no image) and Other Faults Diagnosis and Fixes!!!

post #1 of 56
Thread Starter 
This is an attempt to self diagnose the panel issue whereas it has been diagnosed by the manufacturer with high repair cost. All replies and contribution within is to be taken at your own risk and under no circumstances anyone is held responsible for the instructions or comments.
post #2 of 56
Thread Starter 
I have a Samsung 63C7000 panel that has no display and Samsung has reported a faulty panel and asking for $1k to get the panel replaced. But i decided with the aids of some pro/expert here to carry out a self diagnosis to see if we can revive the panel without the costly bill..
post #3 of 56
Thread Starter 
My unit when being supplied with power, will have its red led indicator showing it's in standby mode and upon pressing the power button (either through the front touch sensitive or remote) the red led indicator will blink in a constant 1 second interval but the 1st few attempt will result it comes back to standby.

Upon a few more power up attempt, the panel will give a quick flash of white (usually is at the left half screen) and the red inidcator will diminish showing the panel is now power up. But it'll have nothing on display not even the standard menu and nothing you can do to get a display. By pressing the power button, it'll go back to standby mode again.
post #4 of 56
OK. This actually sounds most likely to be a main board fault, reasonably common with high end Samsung sets.

For this test you will be referring to the FAST TRACK guide I provided you. (Anyone reading this in future, PM me to get a free copy.)

You have a logic board and a main board in the TV chassis, among others. The main board is the one with all the HDMI etc inputs on it. Colour of main board may vary. They are sometimes green and sometimes blue. There is also a power board -- Samsung calls it an "SMPS board". This connects to the power cord. While the set is in operation, never touch anything on the power board to avoid electrocution.

There is a small orange ribbon going in between the main board and logic board. Very carefully unhook this cable from the main board end.

Unplug the connector going between the power board and main board, at the main board end.

There is a small, 2x2 pin header on the logic board. You need to take an alligator clip, or a jumper setting that would be used on a hard disk, or a paper clip, and jumper the pins numbered 3 and 4 together. Make sure this connection is firm.

Plug the power to the set in. The set should power on and a few test patterns may be displayed on the plasma screen. (If you see these, you know for certain the panel is OK.) It may then shut off, this is OK.

If it does NOT show any patterns: Unplug the set, plug in the connector between the main and power boards, turn on the set again. (You -may- only see brief patterns.) If so, see below.

If the above works (either of the above, with the main unplugged or plugged in) but the patterns don't persist: there is a label next to the connector on the power board which goes to the main board. Please get picture of it so I can see what connections need to be made. You will need some wire ties or hookup wire.

If it shows patterns and they persist: Replace main board.
post #5 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

OK. This actually sounds most likely to be a main board fault, reasonably common with high end Samsung sets.

For this test you will be referring to the FAST TRACK guide I provided you. (Anyone reading this in future, PM me to get a free copy.)

You have a logic board and a main board in the TV chassis, among others. The main board is the one with all the HDMI etc inputs on it. Colour of main board may vary. They are sometimes green and sometimes blue. There is also a power board -- Samsung calls it an "SMPS board". This connects to the power cord. While the set is in operation, never touch anything on the power board to avoid electrocution.

There is a small orange ribbon going in between the main board and logic board. Very carefully unhook this cable from the main board end.

Unplug the connector going between the power board and main board, at the main board end.

There is a small, 2x2 pin header on the logic board. You need to take an alligator clip, or a jumper setting that would be used on a hard disk, or a paper clip, and jumper the pins numbered 3 and 4 together. Make sure this connection is firm.

Plug the power to the set in. The set should power on and a few test patterns may be displayed on the plasma screen. (If you see these, you know for certain the panel is OK.) It may then shut off, this is OK.

If it does NOT show any patterns: Unplug the set, plug in the connector between the main and power boards, turn on the set again. (You -may- only see brief patterns.) If so, see below.

If the above works (either of the above, with the main unplugged or plugged in) but the patterns don't persist: there is a label next to the connector on the power board which goes to the main board. Please get picture of it so I can see what connections need to be made. You will need some wire ties or hookup wire.

If it shows patterns and they persist: Replace main board.

I tried the above steps but either way, ie. with the main to logic orange connection removed and power to main remove and pin 3 and 4 shorted, it doesnt show any pattern and the standby led is not lid NOR with the main to logic orange connection removed but power to main connected and pin 3 and 4 shorted, it doesnt shown any pattern but the standby led lamp is lid and is able to give the panel a short flash but no pattern.

What's next?
post #6 of 56
Can you show me how you performed the 3-4 test jumper?
post #7 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

Can you show me how you performed the 3-4 test jumper?

It happened that i have some spare PCB jumper lying around from other circuitry main board jumper pin as well. It's similar to those you can find in the PC main board. I did done a multi meter test to check the jumper 3 and 4 is shorted out and it confirmed.
Edited by Hifi4Hobby - 11/18/13 at 7:17am
post #8 of 56
Thread Starter 
Quote:
Originally Posted by Hifi4Hobby View Post

It happened that i have some spare PCB jumper lying around from other circuitry main board jumper pin as well. It's similar to those you can find in the PC main board.

Trying to get my smartphone to sync with the PC to upload the photos but having some connection issue now..
post #9 of 56
Thread Starter 
Ok, here're the photos :



post #10 of 56
OK, looks like we will have to jumper the power board to get it to switch on. For that, you will need to post a picture of the labels next to the connector which runs off to the main board, on the power board side. Labels like PS ON, VS ON, 13V, 5.3V, etc.
post #11 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

OK, looks like we will have to jumper the power board to get it to switch on. For that, you will need to post a picture of the labels next to the connector which runs off to the main board, on the power board side. Labels like PS ON, VS ON, 13V, 5.3V, etc.

here's the label..what's our next step?

post #12 of 56
OK, you need to make sure it is unplugged from the main board end.
Take a small piece of wire (cable tie, paperclip, bell wire, etc.) and wire it between the pins labelled PS ON and STD5V.
Leave the jumper on the control board and LVDS (orange wire) unplugged.
Do you get test patterns?
post #13 of 56
Thread Starter 
I was looking for visual damages and i found this part on the power supply board that looks kinda worrying, is that of concern?

post #14 of 56
If you're referring to the black marks around some components that's just a result of heat, nothing to worry about.
post #15 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

OK, you need to make sure it is unplugged from the main board end.
Take a small piece of wire (cable tie, paperclip, bell wire, etc.) and wire it between the pins labelled PS ON and STD5V.
Leave the jumper on the control board and LVDS (orange wire) unplugged.
Do you get test patterns?

Ok, i unplugged the cable from power board to the main board at the main board end, insert a jumper cable on pin 16 and 18, removed the orange cable from logic board to the main board at main board end, shorted logic board jumper 3 and 4, i dont get the standby led when i applied power, so no test signal at all.

I also tried doing the above exactly the same with no shorting to the logic board jumper 3 and 4 and i get also no standby led indicator, so no test signal as well.

What should we be doing next?
post #16 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

If you're referring to the black marks around some components that's just a result of heat, nothing to worry about.

Ok. Usually black mark on PCB board can suggest something not right but since you dont think so, then let skip this and work on others..
post #17 of 56
Quote:
Originally Posted by Hifi4Hobby View Post

Ok, i unplugged the cable from power board to the main board at the main board end, insert a jumper cable on pin 16 and 18, removed the orange cable from logic board to the main board at main board end, shorted logic board jumper 3 and 4, i dont get the standby led when i applied power, so no test signal at all.

I also tried doing the above exactly the same with no shorting to the logic board jumper 3 and 4 and i get also no standby led indicator, so no test signal as well.

What should we be doing next?

No power LED is expected, as the main board controls the power light.
Next step will require a digital multimeter, please show a picture of the one you have.

These TVs are very thin, so airflow is restricted. Odd patterns due to convection can occur because of this.
post #18 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

No power LED is expected, as the main board controls the power light.
Next step will require a digital multimeter, please show a picture of the one you have.

These TVs are very thin, so airflow is restricted. Odd patterns due to convection can occur because of this.

Here's my multi meter..

post #19 of 56
Thread Starter 
I need to ask if we're to test the Vs Va etc, there's only one point of contact, where will one of the two multi meter lead goes to? Earth or Neutral point?
post #20 of 56
The ground on this set is the metal chassis. Find an exposed screw hole, such as the wall mount bracket, and use that.

Set meter to highest DC range (not AC, the DC ranges are marked with a V and solid line/dashed line symbol.) Then check what you get on Vs and Va with the set plugged in, be very careful not to let the probe slip.
post #21 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

The ground on this set is the metal chassis. Find an exposed screw hole, such as the wall mount bracket, and use that.

Set meter to highest DC range (not AC, the DC ranges are marked with a V and solid line/dashed line symbol.) Then check what you get on Vs and Va with the set plugged in, be very careful not to let the probe slip.

Ok, i tested out both Vs and Va and the original value is 1 - 2v below the specified value stated on the panel label. I have adjusted it to conform with the number given. I have also tested out both Vsc and Ve and they turned out to be also 1 - 2v above/below the stated value given so i also adjusted them back to the number given. One thing is, all four point of power reading drops after a few seconds so according to the service manual, it seems this is to be expected?

I am seeing this logic board led flashing slowly though everytime i apply power. It's labeled LED2001 :



I do on and off gets a screen flash (not the whole screen) but usually on the left half of the screen, and it's a white flash.So what's the next step we need to check?
Edited by Hifi4Hobby - 11/18/13 at 8:50pm
post #22 of 56
Is the LED flashing approx once a second or approx once every 5 to 6 seconds?
post #23 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

Is the LED flashing approx once a second or approx once every 5 to 6 seconds?

It's a 5 secs on and 2 secs off kinda of flashing..
post #24 of 56
Thread Starter 
I did some reading and it seems that such flashing seems to suggest the Ysus and Y Buffer board needs replacement but i aint an expert in this so definitely need more of your input on this matter.
Edited by Hifi4Hobby - 11/19/13 at 6:04am
post #25 of 56
Yeah, that would be a Y-main and X-main replacement. You'd need to replace both at the same time. Most likely, it is an X-main fault, due to the flash on the screen (indicates at least partially functional Y-main.) But it's not certain, so I'd suggest you replace both. Usually you don't have to replace the buffer.
post #26 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

Yeah, that would be a Y-main and X-main replacement. You'd need to replace both at the same time. Most likely, it is an X-main fault, due to the flash on the screen (indicates at least partially functional Y-main.) But it's not certain, so I'd suggest you replace both. Usually you don't have to replace the buffer.

Ok, so where can i find the parts?

I did read somewhere that the advisor advised to swap out the associated buffer board as it's difficult to pin point the exact fault and if replacing the X/Y board with a faulty buffer it'll screw the new replacement. How true is that?
Edited by Hifi4Hobby - 11/19/13 at 7:02am
post #27 of 56
That information is only true for older plasmas as far as I know; for newer ones (like this) it doesn't apply.

As for the parts, there should be an LJxx-xxxxxx[A-Z] number on each of the boards. There will be a PCB number and a PBA number; where available, choose the PBA over PCB.

Here's a useful video
http://www.youtube.com/watch?v=R1jmj_foId0

You can buy parts from shopjimmy and other suppliers. Depending on your location, you might also be able to cheaply source them from vendors in China and Korea.
post #28 of 56
Thread Starter 
Quote:
Originally Posted by tom669 View Post

That information is only true for older plasmas as far as I know; for newer ones (like this) it doesn't apply.

As for the parts, there should be an LJxx-xxxxxx[A-Z] number on each of the boards. There will be a PCB number and a PBA number; where available, choose the PBA over PCB.

Here's a useful video
http://www.youtube.com/watch?v=R1jmj_foId0

You can buy parts from shopjimmy and other suppliers. Depending on your location, you might also be able to cheaply source them from vendors in China and Korea.

I found both the X & Y boards having revision AA2. Would the AA1 fits? The visual different mainly on the X board which seems to have one pair more of the green capacitors while the one on my faulty unit has lesser. The revision year is 2010 for AA2 and 2009 for AA1.
post #29 of 56
Thread Starter 
Here's the X & Y board PBA number. But according to the guide, it seems the revision does matter. Mine is AA2 for both.



post #30 of 56
Can you show me what components are different? In general, for Samsung rev numbers, it is the first two characters that are important. The last digit is generally incremented for improvements, so for example Samsung may have made an adjustment to make the boards more reliable but they are still compatible with the original AA1.
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