Samsung UN55H6203AF - No Picture! - No Sound?

[can]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

@TheTesterMan.. Following your advice I tested the M ports with my meter on Diode Check, One lead on the M port and the other on GRD, ( chassis screw ) I started with M3, as soon as I placed the leads, THE PICTURE CAME ON, all LEDs strips seem to be working.. as I lift the the leads the picture goes off (LEDs off) So I continued with all the M- and every time I touch the M- the picture comes back.. so I'm guessing this is a grounding issue?

[TheTesterMan]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

@can.. I should have mentioned that the diode check needed to be done with the power off.. But it seems you are on to something. If you saw all the LEDs light up, then clearly the issue is in the PSU. How & why it is not pulling a proper ground I do not know, I simply do not have enough experience for that type of troubleshooting. If U cannot troubleshoot down to component level, then you may want to simply replace the Power Board

[petehall347]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

hope your meter survived .

[can]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

@can.. I should have mentioned that the diode check needed to be done with the power off.. But it seems you are on to something. If you saw all the LEDs light up, then clearly the issue is in the PSU. How & why it is not pulling a proper ground I do not know, I simply do not have enough experience for that type of troubleshooting. If U cannot troubleshoot down to component level, then you may want to simply replace the Power Board

OK, here is an update! I could not troubleshoot the board completely. I checked every Cap (they all hold charge, and are the right capacitance) All diodes work, everything else seems fine.
I went ahead and replaced the Power board for a new one!

The new board seems to have the same problem... however M1 now exhibits 300+ volts which is good compared to the max 245 V before.

Something else I noticed: there is a test point for 8V on stand by and 13 when the tv is on. This test point always stays at 12.88V regardless if the TV is on standby or on. Is this normal?

With a new board, and all LEDs working. Im out of options.

[TheTesterMan]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

I do not have the TV handy at this moment to verify but if you look at my initial post you can see the pictures and corresponding voltages under Measurements.

Yes, CM863 CNM803 PS_ON should toggle 8 to 13V in response to remote. This voltage comes from the MAIN board and are used to control the Power Board. You need to now start checking all the power regulators on the Main Board, my guess is that one of your Main Board voltages is out.

[TheTesterMan]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

Ok, I applied 40v @ 50mA to each strip and found M4 to be defective. I now need to decide if I open it up and try to repair this strip ( I work for an LED company so I should be able to find replacement LEDs ) or simply purchase a full strip. I'll report back, I think I am going to go ahead and try the repair first.

Its been a while, but I finally went back to this TV and replaced both the M4 ( A and B side ) LED strips and the TV now works great.

Hopefully someone will find this post helpful.

Tester

[JOEYMOLE]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

No idea if i am suppose to post here. I have a Samsung UN55H6350AF . OMG so much time on this tv....Powers on no picture but i have sound. when you power up backlights flash then goes off. I took tv apart all backlights working. Changed main board and tcon board 5 times same response----Did flash light test ..Nothing on screen ..No idea PLEASE HELP!

[neilc6]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

Did you disconnect the main cable from the power supply? Baclights should stay on.

[attainteddragon]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

disconnect one of the ribbon cables that goes between the t-con and the panel driver board.
apply power and see if you get half a pic.
disconnect power.
reinstall the ribbon cable, and then remove the opposing ribbon cable.
apply power.
check if the other half of the screen gives you a picture.

photo of the back of the tv with the rear cover off would be a great way to start too.

[Eliah1]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

Try disconnecting the connector from the Main Bd that come from the Pwr Bd and see if the LED backlights turn on and remain on. You would see the backlights lighting from the holes at the back of the tv.

I know this is a old post but i have the same issue with the same model and when I disconnect the connector from the main board i have the screen light up and stay on. What can I do next. Thanks

[vinceroger69]

Re: Samsung UN55H6203AF - No Picture! - No Sound?

I know this is a old post but i have the same issue with the same model and when I disconnect the connector from the main board i have the screen light up and stay on. What can I do next. Thanks

usually a replacement mainboard will solve this issue