Samsung UE46D6500 doesn't turn on and clicks

[voxahbc]

Hello guys. I have a problem with my Samsung LED Tv UE46D6500 and hope to find a cheaper soultion with your helps.

Here is the situation. I have this tv since 2011 and never had any problem, never got repaired and even cover opened. Recently it's started to not turn on. When I plug the cord stand by led lights steady. When push to button to turn on "Smart TV" logo shows up and turns off with an endless cycle.

I opened the back cover to control the boards as general symptoms shared by people led me to check the capacitors. During the cycle the power board clicks. All capacitors are in very good physical condition, no burn or color change visible. No cracked or bad solder joints visible.

With a multimeter I checked the fuses and they're all good. To identify which board has problems I removed 22pin (to the main board) cable and cables to the led panel then did some measures. Here are the readings:

1 OD_LEVEL 5.3V Max - fluctuating
3 OD_ON/OFF 5V Max - fluctuating
5 GND Continuity checked - OK
7 B13V 12.8V Max- fluctuating
9 B13V 12.8V Max- fluctuating
11 Vamp 13V - constant
13 Vamp 13V - constant
15 GND Continuity checked - OK
17 B5V 0V
19 B5V 5.4V - constant
21 N. C 5.4V - constant

2 P_DIM4 0V
4 P_DIM3 0V
6 P_DIM2 0V
8 P_DIM1 0V
10 B13V 12.8V Max - fluctuating
12 BLU 4.8V - constant
14 GND Continuity checked - OK
16 GND Continuity checked - OK
18 A5V 0V
20 POWER 5.4V - constant
22 N. C 3.4V - constant

Fluctuations are between 0V and the max reading.

There are two high voltage (450V) capacitors and they gave me around 380V



With the results above I assume power board has problem, so any idea, experience or helps to identify where the problem is, are appreciated. I also attached the photos of the power board. Thanks

[Hamie]

Re: Samsung UE46D6500 doesn't turn on and clicks

Mainboard likely.
Unplug the mainboard and test voltages again.
With mainboard unplugged backlight should come on and stay on.

[budm]

Re: Samsung UE46D6500 doesn't turn on and clicks

"17 B5V 0V
19 B5V 5.4V - constant
21 N. C 5.4V - constant
18 A5V 0V"
Are you sure you count the pins correctly? Look at some of your readings, they do not look right.
Without Standby A5 power supply then you cannot have ANY control Voltages, i.e. PS-ON, BLU, etc. but you are showing you do have them. The Standby power supply output is connected to the pull-up resistors to simulate control signals when power supply is not connected to the main board to perform power supply board self-test.
Power supply board BN44-00427A
https://www.shopjimmy.com/samsung-bn...upply-unit.htm

[voxahbc]

Re: Samsung UE46D6500 doesn't turn on and clicks

"17 B5V 0V
19 B5V 5.4V - constant
21 N. C 5.4V - constant
18 A5V 0V"
Are you sure you count the pins correctly? Look at some of your readings, they do not look right.
Without Standby A5 power supply then you cannot have ANY control Voltages, i.e. PS-ON, BLU, etc. but you are showing you do have them. The Standby power supply output is connected to the pull-up resistors to simulate control signals when power supply is not connected to the main board to perform power supply board self-test.
Power supply board BN44-00427A
https://www.shopjimmy.com/samsung-bn...upply-unit.htm

You're right. Somehow, I think in an absence of mind I included pins 21 and 22 and made a shifting in both reading and the table. Anyway I redid the measurement with same conditions (like I did in the previous, all cables except 220V power are disconnected). Here are new readings:

1 OD_LEVEL 5.3V Max - fluctuating
3 OD_ON/OFF 5V Max - fluctuating
5 GND Continuity checked - OK
7 B13V 12.8V - fluctuating
9 B13V 12.8V- fluctuating
11 Vamp 12.5V - fluctuating
13 Vamp 12.9 V - fluctuating
15 GND Continuity checked - OK
17 B5V 5.4V - fluctuating
19 B5V 5.4V - fluctuating

2 P_DIM4 0V
4 P_DIM3 0V
6 P_DIM2 0V
8 P_DIM1 0V
10 B13V 12.8V- fluctuating
12 BLU 4.8V - fluctuating
14 GND Continuity checked - OK
16 GND Continuity checked - OK
18 A5V 5.4V - constant
20 POWER 3.4V - constant

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Ok, now do the same test with everything hooked up and connected, example of testing in #2 below.

[voxahbc]

Re: Samsung UE46D6500 doesn't turn on and clicks

Ok, now do the same test with everything hooked up and connected, example of testing in #2 below.

Here are the readings for two conditions:

1- All the cables connected and TV in stand-by mode (not pushed the power button):

1 OD_LEVEL 0V
3 OD_ON/OFF 0V
5 GND Continuity checked - OK
7 B13V 0V
9 B13V 0V
11 Vamp 0V
13 Vamp 0V
15 GND Continuity checked - OK
17 B5V 0V
19 B5V 0V

2 P_DIM4 0V
4 P_DIM3 0V
6 P_DIM2 0V
8 P_DIM1 0V
10 B13V 0V
12 BLU 0V
14 GND Continuity checked - OK
16 GND Continuity checked - OK
18 A5V 5.4V - constant
20 POWER 0.25V - constant

2- All the cables connected, pushed the power button to turn on and TV started to cycle and click:

1 OD_LEVEL 4.8V Max - fluctuating
3 OD_ON/OFF 4.8V Max - fluctuating
5 GND Continuity checked - OK
7 B13V 12.8V - fluctuating
9 B13V 12.8V- fluctuating
11 Vamp 12.8V - fluctuating
13 Vamp 12.8V - fluctuating
15 GND Continuity checked - OK
17 B5V 5.4V - fluctuating
19 B5V 5.4V - fluctuating

2 P_DIM4 3.3V- fluctuating
4 P_DIM3 3.3V- fluctuating
6 P_DIM2 3.3V- fluctuating
8 P_DIM1 3.3V- fluctuating
10 B13V 12.8V- fluctuating
12 BLU 5V - fluctuating
14 GND Continuity checked - OK
16 GND Continuity checked - OK
18 A5V 5.4V - constant
20 POWER Either 0.25 or 3.3V with the cycle

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Maybe weak/bad startup caps or voltage regulating diode??

[diif]

Re: Samsung UE46D6500 doesn't turn on and clicks

I've had a couple of almost identical Samsung TVs from the same year that showed the Smart TV logo and restarted over and over.
It was bad blocks on the Samsung NAND on the mainboard.

[voxahbc]

Re: Samsung UE46D6500 doesn't turn on and clicks

Thanks for replies. So what do you think guys? Is it power suplly board or mainboard issue? From the readings, I don't think it's mainboard, I assume it's power supply board because it flactuates while mainboard cable disconnected. But the crtitical point with the given conditions (readings and no visible defects) what could be the actual problem to address? capacitors or any other components? I'm asking this because if it's something easy (desolder/solder and change components etc.) I'll go by myself. Otherwise I'll look for a power supply board replacement. Thanks.

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Easy test, with tv unplugged from power, check all the diodes on powerboard, try diode mode, should get a reading in one direction, reverse meter probes, should read 1 or OL if any read off, take out of circuit and test again.

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Good testing video there: https://www.youtube.com/watch?v=ocqnqmBxiqY

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Guess the question is, should the voltages be stable with the mainboard unplugged or should they fluctuate if they should be stable then there's a problem on powerboard side.

[MANNOFSTEEL]

Re: Samsung UE46D6500 doesn't turn on and clicks

can you post a pic of the mainboard ( back)

[budm]

Re: Samsung UE46D6500 doesn't turn on and clicks

Can we see good clear pictures of the whole backside of the TV showing all the boards?

18 A5V 5.4V - constant
20 POWER Either 0.25 or 3.3V with the cycle Right now the standby power supply is steady but the main board is not sending out solid HI command signal (PS-ON/POWER) to turn on the rest of the power supply.

[voxahbc]

Re: Samsung UE46D6500 doesn't turn on and clicks

Thhanks for replies again. I'm sending detailed photos of all the boards.

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Well did you check al the diodes per post #10??

[voxahbc]

Re: Samsung UE46D6500 doesn't turn on and clicks

Well did you check al the diodes per post #10??

I just did. I got a bad diode shorted. It blinks red on the multimeter either way. The others passed the diode test.

[nomoresonys]

Re: Samsung UE46D6500 doesn't turn on and clicks

Ok, easy way to verify is just clip a leg in the middle so it will be easy to re-solder if it's ok and retest out of circuit.

[budm]

Re: Samsung UE46D6500 doesn't turn on and clicks

I just did. I got a bad diode shorted. It blinks red on the multimeter either way. The others passed the diode test.

The diode D9601 tested bad in the circuit because it is connected in parallel with LOW Ohms resistor R960, you can look at the bottom side of the board to see how the Diode and the resistor are connected together.

Samsung BN44-00427A
https://www.shopjimmy.com/samsung-bn...pply-unit.htm#

BTW, we never get to see what Voltages you have (you power up just the power supply board) on the power supply connector when the connector from the power supply NOT connected to the main board.

[neilc6]

Re: Samsung UE46D6500 doesn't turn on and clicks

Have seen lots of main board issues with the D series. Try freezing the NAND with upside can of duster and see if it turns on.