Samsung UN55ES6100F power board output voltages ?

[Wescott12]

Hello everyone, I've searched the forum, got close on 1 thread but it was missing the info that I need...
The tv powers up with no backlight but it passes the flashlight test...
First, I've disconnected the mainboard from the power board (BN44-00503A), still no backlight. Before concluding on bad led strips, I wanted to check voltages at it's connector (CNL802):
Voltage on Pin 1 (or 2) to ground fluctuates from 299v to 321v but nothing between Pin 1 and Pin 9 ...
Shouldn't I read any voltage there ?
I ordered a LED tester online (dont want to dismantle the entire panel if it's only a PSU problem), but meanwhile I figured one of you guys might
have an idea... Thanks for your time...

[R_J]

Re: Samsung UN55ES6100F power board output voltages ?

The led output should be 243v @ 367ma, the fact that it is over 300v would indicate the led string is open. Without any current draw from the led's in the panel, the led output voltage on the power supply board will be high.

[Wescott12]

Re: Samsung UN55ES6100F power board output voltages ?

Hi, thanks for your reply...

Ok, understood, I have over 300v CNL802 plugged or not,
so at least one of the led strips is open...
But should I get anything when I test pin 8/9 to 1/2 on the PSU (with the LED connector unplugged) ?
With schematics would have been easy to figure (wich I tried to find without success)

[R_J]

Re: Samsung UN55ES6100F power board output voltages ?

Look at the back of the board, the supply for the led's is on 8,9, pins 4&6 are just connected together, pins 1,2 are the return but does not go directly to ground, the current through the led string is controlled by Q9101. with no current detected, the led controller will shut the circuit down.

[Wescott12]

Re: Samsung UN55ES6100F power board output voltages ?

Yes, saw that on the rear of the board, but didn't know about the led circuit being disabled if led strip is "open"...

Thank-you very much for your help sir !