Using Samsung Backlight as lighting

[bokkie]

Got a Samsung UE49MU62220, powersupply = BN44-00807H
The screen is broken, not the problem though.
I want to use the unit for lighting.
Without mainboard, so called "Forced Backlight" functions fine ... only ..it's full on.
I would like to be able to dim the "unit"

Unfortunately i can not find schematics/diagram of how the leds are driven, only some snippets here and there since it seems somewhat same for several designs from Samsung.

BLU_PWM on CNM803 from the mainboard seems to be the signal that does this ..but how ?
0.9 - 3.3V(full) should change the level. Could i just get a voltage from the powersupply and run it through a potentiometer or is it some special frequency requirement ?
There is also vr9051, could i abuse this or is it only to limit max. current ?

[yokoono]

Re: Using Samsung Backlight as lighting

If the power supply has a pin called a DIM, the backlight adjustment is done there.
It may be called something else. With a positive voltage of about 3V the baclight is maximum. With voltage 0 (ground) it is minimal

[bokkie]

Re: Using Samsung Backlight as lighting

Well, since i can´t find a diagram or schematics ...

There might be a pin ANA-DIM

edit- attached picture is from a different model, pinout does not match mine, i get 13v on pin 2,3,4,5 pin6=0.4-0.5v only 11 and 12 seem to be ground, rest gives 3.2 3.3 and 5

[bokkie]

Re: Using Samsung Backlight as lighting

man, need new eyes
pinout is on the pcb of course
but not helping much of course

i get 3.2v out of ana-dim and 3.1 pwm-blu

so, if these are outputted from the powersupply TO the mainboard ..yet the mainboard regulates the brightness through software ?! but the header for the backlight is on the powersupply ?!

short pwm_blu or ana_dim to ground (through potentiometer) or what ?
i don´t understand how it regulates the current here

[Biruslapio]

Re: Using Samsung Backlight as lighting

The PSU is generating these voltages as part of the self-test that samsung has, if you wire the PSU manually, simulating a motherboard, then you will need to input voltages into PWM and DIM pins, 1~3V is the variable range for brightness, DC should be fine.