AOC E970SW no backlight

[dick_barton]

Re: AOC E970SW no backlight

Those leds look as though they are identical in brighness.

What is the full board number 715Gxxxxxx

Can you post a good picture of this section of the power supply.

[Sraros]

Re: AOC E970SW no backlight

715g6503-p04-001-001c

[dick_barton]

Re: AOC E970SW no backlight

When all else fails and you have tested most of the components around U801 then the final alternative is to replace the IC.

The manual I attached earlier is similar but not identical to your circuit.

[Sraros]

Re: AOC E970SW no backlight

I replaced U801, with a new one... still nothing, the board reacts the same...

[dick_barton]

Re: AOC E970SW no backlight

That's a pity but it does now rule that out. Can you remove Q801 and test it this time out of circiut.

Can you post a photo of the connector that is connected to the leds

With the leds connected what is the voltage at each pin as you power up. Need to power up when testing each pin. The voltage may shoot up and just as quickly fall so if you have a min/max meter would catch it.

[Sraros]

Re: AOC E970SW no backlight

Dick, I scratched some points on the LED bar to check the leds 1 by 1
In diode mode each one lights up.
I reconnected the set to power and when I put my finger and make a short between some LEDs they slightly power up at some points
Voltage is 0.2V between the 2 conmectors on the LED bar.
The pins between the cables on the LED bar and the connector on the PCB make contact. Tested in diode mode

[Sraros]

Re: AOC E970SW no backlight

Q801 out of PCB:
D - S = 573 and reverse leads S - D = Infinity
D - G = Infinity and reverse leads D - G = Infinity
G - S = Infinity and reverse leads S -G = infinity

[dick_barton]

Re: AOC E970SW no backlight

That definately appears to be good. The internal diode across the drain/source being the only reading.

[dick_barton]

Re: AOC E970SW no backlight

I must admit I've never witness anything like what is shown in your last video.
It would be interesting to see what others think.

[Sraros]

Re: AOC E970SW no backlight

I gave it up. It was fun to search around, but either way screen size was too small to do it sth