Acer Aspire 5732z - No backlight on LED panel!

[JaYmEz]

Hello everyone,

When this laptop was bought it came with an LCD panel with inverter, it worked for about 2 years until the backlight burned out.
Then it was replaced with an LED panel (with an adaptor replacing the inverter).
At the time this change was made i couldn't control the brightness, this was the only problem, it worked fine like this for couple of months
Now there is no backlight.

Here is the motherboard diagram:
https://dl.dropboxusercontent.com/u/...z_LA_4853P.pdf

I know that the problem is the backlight because if i put a lamp on the side of the LED screen i can see the video outpup.

Voltages on the JLVDS1:
->ON state without the LED panel connected:
Pins - Voltage
1 - 3,3v
32 - 3,1v
34 - 3,1v
36 - 3,3v
38 - 19,2v
40 - 19,2v

->ON state with LED panel connected:
Pins - Voltage
1 - 3,2v
5 - 1,2v
7 - 1,1v
11 - 1,1v
13 - 1,2v
17 - 1,1v
19 - 1,2v
23 - 1,1v
25 - 1,2v
29 - 3,3v
31 - 3,3v
32 - 3,2v
33 - 3,3v
34 - 3,2v
35 - 3,3v
36 - 3,2v
38 - 19,2v
40 - 19,2v

Now the voltages on the 7 pin inverter connector:
Pins - Voltage
1 - 0,0v
2 - 0,0v
3 - 3,2v
4 - 3,2v
5 - 0,0v
6 - 19,2v
7 - 19,2v

I suspect the brightness voltage. Any hand on this problem would be very appreciated.
Thank you! =)

[JaYmEz]

Re: Acer Aspire 5732z - No backlight on LED panel!

Problem solved, the issue was in the adaptor pcb, the one that replaces the inverter, one of the paths was open, the one that takes the 19,2v to the LED panel, i made a shunt with a wire and it's working now. Still it doesn't control the brightness.

[dj_ricoh]

Re: Acer Aspire 5732z - No backlight on LED panel!

because its converted?

adjust with inverter and now converted.

not the inverter handle the brightness ?

[JaYmEz]

Re: Acer Aspire 5732z - No backlight on LED panel!

No, now there are only the adaptor and the LED panel, the inverter was replaced by the adaptor. This adaptor only changes the connection from the motherboard to the LED panel, and it doesn't convert anything, it only redirects two voltages of 3,2v and two voltages of 19,2v to the LED panel.
The brightness now has two possible positions, one in full bright and another one at half bright, changing by keystroke Fn+cursor key.
The problem of no backlight was in the adaptor pcb, the 19,2v voltages were not reaching the LED panel, now it is solved and it's working well.
Thank you.