Samsung UE46ES5505KXXE power issues (i believe)

[mortenlp]

Hi guys
I am troubleshooting the power board (PD46A1_CSM BN44-00502A) in my samsung TV.
(UE46ES5505KXXE).

Do any of you know the correct way to "activate" this power-board, and might i need other cables that the AC-outlet connected in order to achieve that?.

I have been toubleshooting the board to the best of my ability from guides online by measuring output voltages on the pins going to the logic-board. However as i have been able to get very little response from the board i am a bit afraid that i might not have managed to "activate" the board correctly.

The pins read the following (as seen in the attached picture), and i have measured two non-zero voltages between each pins and GND-pins.
1: B13v
2: PWM_DIM
3: B13v
4: B13v
5: Vamp
6: BLU on_off
7: Vamp
8: GND
9: GND
10: GND
11: B5v
12: A5v (5,28v)
13: B5v
14: Power on_off (3,29v)

In order to "activate" the board i have tried the following:
A) Connecting Power on_off (pin 14) to GND
B) Connecting Power on_off (pin 14) to A5v (pin 12)

However the voltages on the remaining pins are unchanged.

Any info on how this board should be activated would be awesome, so that i can either deem it healthy or order a replacement.

Thank you in advance.

Best wishes
Morten

P.S: The same board is discussed in this thread https://www.badcaps.net/forum/showthread.php?t=37582 however i did not want to "hijack" another thread.

[budm]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Does the backlights stay on when you power up the TV without the main board cables connected to the power supply board?
Also upload the pictures that show the whole back side of the TV so we can see all the boards.

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Thank you for the reply.

The screen remains black also when the logic board is not connected. (Is this enough to answer you question about the backlight or might the backlight be on without being visible onscreen?)

I have attached photos of the TV with no backplate, and the power-board placed where it should be (but with no cables attached).

Thank you guys in advance.

Best wishes
Morten

[dick_barton]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Did you test the power supply isolated from the rest of the TV set? If not it may be worth your while isolating it and trying one more time and check what voltage you have on Power On/Off pin.

[budm]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Thank you for the reply.

The screen remains black also when the logic board is not connected. (Is this enough to answer you question about the backlight or might the backlight be on without being visible onscreen?)

I have attached photos of the TV with no backplate, and the power-board placed where it should be (but with no cables attached).

Thank you guys in advance.

Best wishes
Morten

But you have the LED backlights connector (grey and blue wires) not connected in your picture. You have to have LED connector in place but not the connector that goes to the main board.

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Did you test the power supply isolated from the rest of the TV set? If not it may be worth your while isolating it and trying one more time and check what voltage you have on Power On/Off pin.

I did my measurements while the power-board was disconnected.
The Power on_off waltage was 3,29v.
What does that tell me?...

[budm]

Re: Samsung UE46ES5505KXXE power issues (i believe)

I did my measurements while the power-board was disconnected.
The Power on_off waltage was 3,29v.
What does that tell me?...

That means the PS-ON command Voltage is present (the board has pull-up resistors for self test) to turn on the PFC Voltage booster (you should have about 400VDC between the two legs of the main filter cap's legs) and the rest of the power supply section.
So did you put the LED connector back in place to see if the backlights are on when the cable between the main board and the power supply board is not in place.

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Thanks a lot for the input!

STATE
LED-power: Connected
mainboard: Disconnected

LED VISUALS:
There is no light to be seen from the either back nor front. However there are no holes in the back chassis to peek through. So i dont know if the LCD-panel MIGHT be black and thus hiding the LED-backlight?

VOLTAGE MAIN CAP:
I am getting 389vdc over the biggest capacitor on the board (the main filter capacitor?).

VOLTAGE LED CONNECTOR:
Measuring the DC voltage between chassis the LED powerpins i am getting:
R+ 108mv
R- fluctuating 1-10mv
L+ 0v
L- 350mv

Thank you in advance.
Morten

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Based on the above observations, would it seem like a pretty safe bet that the power-board is at fault?

[thoma]

Re: Samsung UE46ES5505KXXE power issues (i believe)

ftp://helpedia.com/pub/temp/datashee...t_track_guide_[SM].pdf

ftp://helpedia.com/pub/temp/datashee...itors/Samsung/

may be help!

regards thoma!

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

I am not sure how to use the two urls?

Any thoughts on whether or not it might be safe to order a new power-board?

Best wishes

Morten

[budm]

Re: Samsung UE46ES5505KXXE power issues (i believe)

VOLTAGE LED CONNECTOR:
Measuring the DC voltage between chassis the LED powerpins i am getting:
R+ 108mv
R- fluctuating 1-10mv
L+ 0v
L- 350mv

If that is all you get in mV range at the LED connector pins (without having the main board connected), then you do have problem with the LED Boost converter circuits, as shown on the chart on the board, the DCV should be around 191VDC.
I would really look at the board really close to see if you have any bad solder joints first especially on the transformer's legs and the power devices mounted on the heatsink, you may want to do some solder touch up on them.

BTW, the fuse FP802S is good?

[CapLeaker]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Since both strings aren't supplying power, I'd be looking all over that power board too first.
Maybe upload a nice clear, high res shot of the back of the PSU?

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

I would really look at the board really close to see if you have any bad solder joints first especially on the transformer's legs and the power devices mounted on the heatsink, you may want to do some solder touch up on them.

BTW, the fuse FP802S is good?

The fuse is good along with the other one.


Thanks again guys.

I have looked closely at the board and have not been able to see anything conclusive... but i have a couple of suspicions.

Suspicion 1: On one of the components have contact between the first three legs. Also there seems to be some corrosion taking place. Might this be the issue? See attached photo.


Suspicion 2: Another components exhibits what MIGHT be melt marks? Maybe it has gotten really hot at some point? Don't know it that might make sence? See attached photo.


Along with the above photos I have attached a photo of the top and the back of the PSU. Also 4 closeups of the back board.












About bad solder-joints: I was not able to tell that any were bad. Should i just reflow a lot of them at random or might there be some hints i am missing?

Do you think that i am i getting warmer?

Best wishes

[mortenlp]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Hi Guys

I went ahead and orderen a new AC-board and now the tv works like a charm!

Thank you so much for you help especially budm and CapLeaker you are the best!

Cheers
Morten

[Iamwally]

Re: Samsung UE46ES5505KXXE power issues (i believe)

Hi Morten. Might I ask where you ordered new board from? I have similar problem. I think I also had a bad led strip as well. I think I need to start with power board first as the voltages are all wrong at led connector. Would love to repair existing board to save some money but not sure how to go about that exactly. Only discoloration on board that is visible is around the 4 black diodes near led connector. People mention bad ic9101 but can't seem to find part number to order it. I have a suspicion that the bad led strip is shorted and that blew something in led driver circuit. Any info you could give would be great.

Thanks,

John