Lenovo G580 7981P accidently shorted Q83

[Technolix]

Hi,

I've bought 3 Lenovo G580s from a friend, all with different defects.

On this particular board, the 7981P with discret graphics, he shorted Q83 near the LVDS-Connector by dropping the LVDS-Plug on to Q83 while under power.

I then replaced Q83 from another board but still no luck.

What else do I should check? The board starts but no display. Using Vga, my monitor says out of range but is capable of 1920x1080.

I've attached the schematic plus top and bottom of the board. I've circled the replaced component.

[piernov]

Re: Lenovo G580 7981P accidently shorted Q83

Does the OS actually boot? (ie. is it really a "no display" situation and not a "not POSTing"?)
Shorting Q83 to ground shouldn't be that bad, something else have probably happened. It sounds like it is only for the camera, and a quick short to ground on +3VS shouldn't have destroyed anything else.
Check voltage on all pins of Q83 to make sure everything is ok here.

[Technolix]

Re: Lenovo G580 7981P accidently shorted Q83

Hi,

I have no hdd with a OS on it but I've cross checked with a working QIWG6 LA-7988P board, where I have 3.3V on Pin 3 and 2 of Q83.

On the LA-7981P I have 3.3V on Pin 3 but 0V on Pin 2.

I've bought the working LA-7988P Notebook to upgrade it, so the LCD, cable etc. are all functioning.

[Technolix]

Re: Lenovo G580 7981P accidently shorted Q83

Seems I'm missing the 3V line.