Re: Samsung 4K UN55KU6490 backlight issue

At a blank input screen the Ana_dim acts the same although backlights turn off when the backlights get to 18

Re: Samsung 4K UN55KU6490 backlight issue

263V.
A bit more playing around with it. When I get the Netflix sign in page up on it the tv acts normal. I can adjust the backlights to minimum. At max backlight I have 255v across my backlights.
Checking the ana_dim pin from the main board with the backlights at 20 it’s 3.3 and drops by .3V each step down on the backlight. So at 19 it is 3.0V, 18 2.7V, 17 2.4V, 16 2.1V, 15 1.8V, 15 1.5V until down to 10 when it get to 0.
So it seems it just has issues when there is no input so a blank screen.

Hey,
I have a Samsung 55” 4K curves TV UN55KU6490F.
The TV started flashing it's backlights on and off. On for not even a second and stay off for up to a minute.
I pulled the back off and checked the voltages on the power board they seemed ok. I'll post a photo with them.
I pulled the panel off and checked the LEDs when they flash on they all flash on so I don't think it's the LEDs.
I started playing with the settings and found that when I have the backlights at 20 (scale is 0-20) the tv stays on and quickly flashes off once every couple of minutes.
...

Re: Sharp LC-70C8570U

Never mind about the negative voltages haha probs were backwards ��

Re: Sharp LC-70C8570U

See the photo attached.
I did this quickly before I left for work but I'm pretty sure I Got all the pins numbered right.
Everything looks good to me except PWM1 & PWM2.
I did notice all my voltages were reading as negative. Is this normal?
Unless I accidentally had my meter probs connected to my meters backwards but I doubt it 0.o...

Re: Sharp LC-70C8570U

Hey Guys, this is the only thread I can find similar to a problem I have. I’ve got a lc70c7450u,l. It had a dead main board which I replaced with a used. The original problem was it was completely dead. Would flash three times then 1 quick.
The new board fixed this but my backlight won’t come on now. I have a picture with a flashlight. I’ve tried hard resets. I’m missing my PWM1 signal jumpering it out turns the backlights on.
I’m guessing the t-con board is bad.
Does anyone have a schematic for this?