Samsung UN46ES6003FXZA Power Supply issue

[DesertRat]

Hi all, I could use some help. I'm getting a reading on the big cap that's bouncing between 389~379 volts, the LED strips are just flashing on and off with the main board disconnected. When the main board is connected it's giving the symptoms similar to those in this youtube video:

https://www.youtube.com/watch?v=sQtpGflfa-k

LED strips check out to be all working, as I replaced some of the LEDs that were bad.

I've included pics of the power supply board both top and bottom. In the photo's I noted which parts I have already replaced and are new. Just note if you see the red text.

I know the IC9101 (SLC2012M) is a common fault for this board, so I made sure I installed a new one to eliminate that as a possibility. (Through reading other threads here).

Any help is greatly appreciated. TIA!

[CapLeaker]

Re: Samsung UN46ES6003FXZA Power Supply issue

What voltages do you get on each string on the LED connector?

[budm]

Re: Samsung UN46ES6003FXZA Power Supply issue

1) Monitor the Voltage on pin 2 (R+ Anode of the first LED string) of the LED connector to see if it goes up way above 190V with ref. to chassis GND when the LED's flash off. If it does then you have bad connections, connectors, LED in the LED string some where.
2) inspect all the solder joints of the transformer legs, especially on the rivet feed through.
3) What kind of replacement LED's did you use? You may have same issue like this one: https://www.badcaps.net/forum/showthread.php?t=73769

Samsung BN44-00502A
https://www.shopjimmy.com/samsung-bn...led-board.htm#

[DesertRat]

Re: Samsung UN46ES6003FXZA Power Supply issue

1) Monitor the Voltage on pin 2 (R+ Anode of the first LED string) of the LED connector to see if it goes up way above 190V with ref. to chassis GND when the LED's flash off. If it does then you have bad connections, connectors, LED in the LED string some where.
2) inspect all the solder joints of the transformer legs, especially on the rivet feed through.
3) What kind of replacement LED's did you use? You may have same issue like this one: https://www.badcaps.net/forum/showthread.php?t=73769

Samsung BN44-00502A
https://www.shopjimmy.com/samsung-bn...led-board.htm#

1) voltage on pin 2 tops out at 119 volts then drops down and rises back to peak at 119.

2) checked all the solder connections on the transformer and they appear to be in good shape. I did resolder them prior to posting, sorry I forgot to mention that.

3) LED Series TS731A 3V 150 mA. 7032 is the LEDs I used to replace the bad ones. I did check each one by the next one to verify connections for series. I'll read through the thread you linked and see if I done something wrong there.

[DesertRat]

Re: Samsung UN46ES6003FXZA Power Supply issue

What voltages do you get on each string on the LED connector?

Not sure if this is what you're meaning, but here goes.

Pin 2 =119 ~ 85 volts

Pin 7 = 20 ~ 15 volts

As the LEDs flash the power peaks to the higher number, then drops to the lower and recycles. Negative probe grounded to chassis.

[DesertRat]

Re: Samsung UN46ES6003FXZA Power Supply issue

With LED connection disconnected I get:

Big cap = 392v steady

Pin 2 = 260v cycling down to 256-7v then back to 260v

Pin7 = 0v

Hope this is helpful.

[budm]

Re: Samsung UN46ES6003FXZA Power Supply issue

If you look at Voltage chart on the power supply board, the LED Voltage is 191V @ 367mA.

[DesertRat]

Re: Samsung UN46ES6003FXZA Power Supply issue

Budm and Capleaker,

Thank you both for the help. I took the panel off again and found that one of the leds had blown, it had the telltale black spot. I replaced it, and had to track down why it was still only lighting up half of the strip. Turns out it was a bad connection on two leds side by side down the line. I fixed that issue and got it to light the entire strip. Each strip reads on the led strip tester at 79.4 volts when good. Anything different indicates a problem, I usually saw a higher number like 81.?v or 82v at the most.

I put the panel and back together and hooked up the power supply only, (other boards removed), and viola, the lights came on and stayed on like they are supposed to under these circumstances. I checked the voltage on pin 2 and got 190.4 volts. So it looks like the led strip or strips were indeed the problem. Thanks again!

[CapLeaker]

Re: Samsung UN46ES6003FXZA Power Supply issue

good to hear that you got it fixed!

[budm]

Re: Samsung UN46ES6003FXZA Power Supply issue

I hope you use LED that can handle at least 400mA otherwise it will burn up, 50mA rated LED is not going make it..
Make sure to turn down backlights on all input also.

[DesertRat]

Re: Samsung UN46ES6003FXZA Power Supply issue

good to hear that you got it fixed!

Thanks again Capleaker!

I hope you use LED that can handle at least 400mA otherwise it will burn up, 50mA rated LED is not going make it..
Make sure to turn down backlights on all input also.

I'll turn it down as low as I can. This is the LED I used for the replacement, LED Series TS731A 3V 150 mA. 7032. That's all I can find even thru China.

[CapLeaker]

Re: Samsung UN46ES6003FXZA Power Supply issue

Just remember that LED's are current controlled, not voltage controlled. ;