Samsung UN60H6203AFXZA steady flashing backlights

[hidperf]

After spending unknown hours searching the web, I keep ending up here so I'm hoping someone can help me with my problem.

I did find this thread https://www.badcaps.net/forum/showthread.php?t=69298 but the OP didn't report back on his results.

As the title says, I have a Samsung UN60H6203AFXZA and as soon as I plug it in, the LED backlights begin to steadily flash. The TV does not power up that I can tell. I get no boot-up sequence or sound.

Power supply board is BN44-00775A. I don't see any bad caps or signs of excessive heat anywhere on the boards.

If I unplug the main board from the power supply board, but leave the LEDs connected, I still get the steady blinking of the LED backlights.

If I reconnect the main board and unplug the LED backlights from the power supply board the stand-by LED will blink a few times (I counted 6) but it doesn't seem to respond when I press it. I've tried shining a light through one of the holes but I can't see anything showing up on the screen.

With power connected to the power supply, the main board and LEDs disconnected, and the negative probe of my multi-meter connected to the board grounding screw, the voltage readings are as follows.

Power board output
CNM803

1 A13v = 12.93v
3 A13v = 12.93v
5 A13v = 12.93v
7 A13v = 12.93v
9 GND = 0
2 UD = 2.35v
4 PWM_BLU = 3.35v
6 PS_ON = 4.55v
8 GND = 0
10 GND = 0

LED connection - LED strips NOT connected
CNL802

D+ = 465v
D+ = 465v
Nc = .002v
S- = .002v
Nc = .001v
S+ = .001v
Nc = .001v
D- = -.002v ??
D- = -.002v ??

LED connection - LED strips connected and flashing, which made it difficult to get accurate measurements.

CNL802

D+ = 103-112v
D+ = 103-149v and rising
Nc = -.006-.013v
S- = ~35v
Nc = -.003-.013v
S+ = -.06-.08v
D- = -.166- -.3v
D- = -.3v

I also tested the LED strips with an LED tester and got these results.

Checking the LED plug connections A in the attached photo = 77v
Checking the LED plug connections B in the attached photo = 48.3v

I did read in this thread that LED voltage could possibly be 113v, but I'm not sure if that applies to the exact model.
https://www.badcaps.net/forum/showth...ht=bn44-00775A

So, from all that information, my hunch is bad LEDs. But the fact that the TV doesn't seem to power up with the LEDs disconnected is throwing me off.

Thoughts?
More info needed?
Next steps?

Thank you in advance!

I've attached several pictures of the boards and connections.

[tvtimmy]

Re: Samsung UN60H6203AFXZA steady flashing backlights

You have some burnt out leds.

[R_J]

Re: Samsung UN60H6203AFXZA steady flashing backlights

I agree, bad led's or bad plug connection, your test of CNL802 S- and S+ should be the same as those two pins are connected together, so maybe check that your plug does'nt have issues.
Pins 1&2 connected together
pins 3,5&7 No Connection
Pins 4&6 connected together

[hidperf]

Re: Samsung UN60H6203AFXZA steady flashing backlights

You have some burnt out leds.

I agree, bad led's or bad plug connection, your test of CNL802 S- and S+ should be the same as those two pins are connected together, so maybe check that your plug does'nt have issues.
Pins 1&2 connected together
pins 3,5&7 No Connection
Pins 4&6 connected together

I was thinking LEDs myself, but this is a first for me so I thought I'd ask some experts.

R_J, are you saying I should check voltage between 1&2 and between 4&6? With the LEDs unplugged I assume?

[R_J]

Re: Samsung UN60H6203AFXZA steady flashing backlights

No, that's not what I am saying, Look at the back of the board and you will see what I mean.

D+ = 103-112v
D+ = 103-149v and rising
Nc = -.006-.013v
S- = ~35v <--------- This connection
Nc = -.003-.013v
S+ = -.06-.08v <--------- And this connection are the connected together
D- = -.166- -.3v
D- = -.3v
The voltages can not be different, If they indeed ARE different I suspect the plug is not making proper connection between S- and S+

Also NC means NO CONNECTION. there will be 0 volts on those pins

[hidperf]

Re: Samsung UN60H6203AFXZA steady flashing backlights

No, that's not what I am saying, Look at the back of the board and you will see what I mean.

D+ = 103-112v
D+ = 103-149v and rising
Nc = -.006-.013v
S- = ~35v <--------- This connection
Nc = -.003-.013v
S+ = -.06-.08v <--------- And this connection are the connected together
D- = -.166- -.3v
D- = -.3v
The voltages can not be different, If they indeed ARE different I suspect the plug is not making proper connection between S- and S+

Also NC means NO CONNECTION. there will be 0 volts on those pins

I gotcha now. I pulled the board and the traces look good.

Tested S- and S+ again with the LEDs in place and they were the same, though jumping around a bit as the LEDs flashed.
I figured the NC had nothing going to it. My meter was showing negative voltage so something must be going on there.

Thanks for the help!

I've got another older Samsung that I think has bad caps. That's my next project.

[R_J]

Re: Samsung UN60H6203AFXZA steady flashing backlights

The traces are likely ok, but If the wire from the panel that connects to pin4 was loose in the plug, or if the wire from pin 6 was loose and not making good contact, the entire led string would look open to the circuit.
The voltage on pins 4&6 should be aprox. half the voltage of D+ which should be 326VDC but if the led string is open or has led current issues, the led drive controller ic will shut off the boosted voltage and the voltage will drop to around the 100vdc basic VD supply.

[hidperf]

Re: Samsung UN60H6203AFXZA steady flashing backlights

Well, the LED back lights were definitely bad. Replaced them and they tested right at 112v.
But when I put it back together, I now have this.

I was hoping I just didn't attach one of the ribbon cables for the T-Con board but I rechecked and they're all good.

[hidperf]

Re: Samsung UN60H6203AFXZA steady flashing backlights

Well, the LED back lights were definitely bad. Replaced them and they tested right at 112v.
But when I put it back together, I now have this.

I was hoping I just didn't attach one of the ribbon cables for the T-Con board but I rechecked and they're all good.

Anyone want to buy a Samsung UN60H6203AFXZA for parts? Brand new LEDs!

[ShatterMasters]

Re: Samsung UN60H6203AFXZA steady flashing backlights

I'd be interested in the PS board?

[MrC10-85]

Re: Samsung UN60H6203AFXZA steady flashing backlights

Anyone want to buy a Samsung UN60H6203AFXZA for parts? Brand new LEDs!

What's the pet number on the led strips I will have to replace mine since I'm having the same issue and I already replaced the power board.

[hidperf]

Re: Samsung UN60H6203AFXZA steady flashing backlights

I'd be interested in the PS board?

ShatterMasters, I didn't see your reply. I still have the board if you're interested. I pulled all the parts from the unit before I trashed it.

What's the pet number on the led strips I will have to replace mine since I'm having the same issue and I already replaced the power board.

I don't have the part number, but I bought them from Shop Jimmy. If you put your model number in there, it'll show you what fits.