Samsung UN40H6203AFXZA, no backlight or picture

[joeblah]

Hello all,

Would really appreciate anyone's input on this. UN40H6203AFXZA, no LEDs lit. I started by looking through the following thread:
https://www.badcaps.net/forum/showthread.php?t=58767

All measurements to main board from CNM803 look within tolerance. Bridge rectifier readings are good. It's the measurements from CNL802 that I'm concerned about. Power board P/N is BN44-00773C.

I also looked at the LED strips and nothing looks charred (as it did in the aforementioned post). I tried to power a strip (strip P/N D3GE-400SMA-R2) without success (my Agilent DC power supply only goes to 60VDC, but that should have been enough to power one strip... I think). Other known good LED strips power up fine from the same DC supply.

Back to CNL802; at D1+ I get 176VDC, all other pins at CNL802 are below 20mV. Resistance between D1+ and chassis is ~16MΩ.

Trying to decide whether it's the power board or LEDs? Thanks for any suggestions!

-Joe

[budm]

Re: Samsung UN40H6203AFXZA, no backlight or picture

If you at the chart printed on the board, the LOADED LED Voltage is 151.8V since you are getting 176V it means there is open circuit in the LED string.
http://www.shopjimmy.com/samsung-bn4...er-supply.htm#
Pictures provided by shopjimmy.

[CapLeaker]

Re: Samsung UN40H6203AFXZA, no backlight or picture

agree on budm's comment above. x2

[joeblah]

Re: Samsung UN40H6203AFXZA, no backlight or picture

Awesome, thanks budm and CapLeaker!

[budm]

Re: Samsung UN40H6203AFXZA, no backlight or picture

Make sure to use current limiter when testing the LED.

[joeblah]

Re: Samsung UN40H6203AFXZA, no backlight or picture

Make sure to use current limiter when testing the LED.

Thanks budm, will do.