Samsung UE46F5370SS dark, LED blinking

[Bernhard]

Dear all,
my LED TV Samsung UE46F5370SS is (quite) dead. It seems to be the power supply. Instead of 13V I've only around 9V, the LED backlight is dark. The voltage of the backlight is around 185 V. I took my power supply and externally pulled up the 9V to 13V (appr. 700 mA). Now the TV begins more to live: The LEDS are flashing (every 3...5 seconds for a duration of 0.2 sec) and I could see a picture on the screen.
Has somebody experience with this sympthom? How can I repair the power supply? Has somebody a schematic diagram of the power supply? A similar schematics might also help to get an idea how the power supply works.
Would be graet :-)

Best regards

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking

Your SMPS is a BN44-611A or D?!
But first disconnect cable between mainboard and Power!
What happens?
Then connect this cable again!
Disconnect cable between mainboard and T-Con!

Look in this Forum LCD TV and Monitor basic troubleshooting guides

there are a lot of infos!

regards thoma!

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking





Wait until GET MANUAL appears!!!!

[Bernhard]

Re: Samsung UE46F5370SS dark, LED blinking

Thanks for your fast reply!

My SMPS is a "D" Type: BN44-00611D.

When I disconnect the cable from the SMPS to the mainboard nothing happens. The backlight is still dark. The backlight LED voltage is around 190V. The voltages on the negative side of the two LED strings are around 40-50V. The 13V for the mainboard supply have only 8.6V.

As I had no schemtics I checked by vision and saw that one 8 pin DIL IC has a small bump. Unfortunately I cannot read the label of the IC. Nearby is the high voltage MOS FET 13NM60N (ST) and the high voltage diode BYV 29X (NXP). I checked the Gate of the MOSFET and found that the pulses are missing.

So I guess that the IC is damaged and would also change the MOSFET and the diode,

My problem is that I don't know the name of the IC (SMPS controller ??)

Would be great to know the type and where to order !!!!

Best regards,
Bernhard

[ReeceyBurger123]

Re: Samsung UE46F5370SS dark, LED blinking

If I remember theres some resistors for the Pfc that break out the solder casuing low pfc which means low output. Have you an image of the whole under and top side of the board ?

[budm]

Re: Samsung UE46F5370SS dark, LED blinking

Pictures provided by shopjimmy.
These board are known for bad solder joints on the transformer legs and on the rivet through hole solder joints.
When running the power supply/LED driver board by itself, check the DCV between the two legs of the main filter cap to see if you have close to 400VDC or not.

[budm]

Re: Samsung UE46F5370SS dark, LED blinking

You need to leave the Black probe on the chassis, then leave the read probe on 1+ pin of connector CNL802 THEN apply the power to the board and see if the DCV jumps higher than 190VDC and then drops down to 190VDC 5 seconds later or not, do the same on 2+, 3+, and 4+.

[dick_barton]

Re: Samsung UE46F5370SS dark, LED blinking

Shopjimmy do a repair kit for that power supply

http://www.shopjimmy.com/samsung-bn4...repair-kit.htm

[Bernhard]

Re: Samsung UE46F5370SS dark, LED blinking

SMPS board: BN44_006111D


Yes, I have around 400 V at the big Elco 450V / 100uF. Also around 190 V at +1 for the backlight LED.

What I'm missing are the trigger (control-) pulses at the Gate (red arrow) of the high voltage transistor. As there is a small bulge on the control IC (red cricle) I guess and hope that this part is damaged.

I want to order it, but I don't know the IC's type, because I cannot read the label.

So, is there anybody who has a circuit diagram or can give the name of the IC? Many thanks in advance !!!

@dick_barton: I have no access to www.shopjimmy/samsung-bn4....repair-kit.html

Best regards

[dick_barton]

Re: Samsung UE46F5370SS dark, LED blinking

For access to Shopjimmy try:-

http://www.anonymox.net

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking

http://lcd-television-repair.com/new...o_Display.html

http://www.ebay.com/itm/Samsung-BN44...-/272184193534

https://www.amazon.com/Samsung-BN44-.../dp/B01DCLGQV0

For shop Jimmy you need a proxy server to reach!!!!

[budm]

Re: Samsung UE46F5370SS dark, LED blinking

SMPS board: BN44_006111D


Yes, I have around 400 V at the big Elco 450V / 100uF. Also around 190 V at +1 for the backlight LED.

What I'm missing are the trigger (control-) pulses at the Gate (red arrow) of the high voltage transistor. As there is a small bulge on the control IC (red cricle) I guess and hope that this part is damaged.

I want to order it, but I don't know the IC's type, because I cannot read the label.

So, is there anybody who has a circuit diagram or can give the name of the IC? Many thanks in advance !!!


@dick_barton: I have no access to www.shopjimmy/samsung-bn4....repair-kit.html

Best regards

That section you are looking at is the PFC Voltage booster section, that ICP805, the power MOSFET QP801, the diode DP80? next to it are for the PFC and it is WORKING otherwise you will not have the 400VDC on the main filter cap and the 190VDC to feed the boost converter circuit of the LED driver circuit , you are working on the wrong section (PFC). BTW, 'P' in the designator represent PFC.
So did you leave the red probe on the 1+ BEFORE turning on the TV to see if the Voltage goes up to >190VDC and then drops down? That is very important info we need, hopefully your meter is fast enough top catch the Voltage spike.
BTW, what did you use for GND ref. when you are looking at the GATE?

[Bernhard]

Re: Samsung UE46F5370SS dark, LED blinking

Dear all,

thanks a lot for your help !!!

But I'm still looking for a schematic diagram of the Power Supply Board SAMSUNG BN44-00611D. I'm quite sure that the power controller IC is damaged, but I have no reference number to order and change.

WANTED:
- Schematics Samsung BN44-00611D
- Reference of damaged 8 pin IC

Thanks in advance

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking

http://www.elektroda.pl/rtvforum/top....html#15151870

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking

http://www.elektroda.pl/rtvforum/top....html#15758583

https://www.badcaps.net/forum/showth...=25810&page=14

[thoma]

Re: Samsung UE46F5370SS dark, LED blinking

http://**************/ic_power/

[budm]

Re: Samsung UE46F5370SS dark, LED blinking

Dear all,

thanks a lot for your help !!!

But I'm still looking for a schematic diagram of the Power Supply Board SAMSUNG BN44-00611D. I'm quite sure that the power controller IC is damaged, but I have no reference number to order and change.

WANTED:
- Schematics Samsung BN44-00611D
- Reference of damaged 8 pin IC

Thanks in advance

Post #9 Yes, I have around 400 V at the big Elco 450V / 100uF
Like I said, you do have 400VDC on the main filter cap so THAT PFC ICP805 (P for PFC) is fine.
Trace the Gate pin of the PFC Power MOSFET and see that it goes to that IC. Why are you insisting on working in that PFC section?
I am out, good luck.

[vinceroger69]

Re: Samsung UE46F5370SS dark, LED blinking

http://www.shopjimmy.com/samsung-bn4...repair-kit.htm