No display on notebook screen, but external monitor works

vvozar

Hello all,

Acer Aspire 7720z is not displaying anything on its screen - just black screen. Not even faint/dim image at all. On external monitor everything works fine.

Now, here is what I tried but nothing helped:
- checked all combinations when displaying on two monitors, no image even without external monitor plugged
- reinstalled video driver
- reinstalled whole Windows OS
- upgraded to newer BIOS version
- dissasembled notebook to check if all wires are properly connected (twice)
- bought new screen inverter and tested it

Notebook has Intel(R) 965 GPU. Gpu chip on motherboard looks normally, without any signs of melting or overheting. Notebook is not overheating at all, temperature sensors give reasonable values.

I know it could be screen backlight problem, but I would really like to be sure before starting adventure of replacing LCD's CCFL backlight lamp.

Although it is black screen all the time, I can see something like flicker when starting windows or when changing screen resolution, but I really have to pay close attention to see that flicker, sometimes I think I am just imagining it.

Any ideas? Suggestions? Help? What to try, or it definatelyy is bad backlight.
Appreciate.

vvozar

I would like to check if lid-close switch is not making this problem, but don't know where it is located. Or if it is some magnet how could I check if it properly works. I have set Windows to go to sleep mode when closing lid and it works (on external monitor of course), but wonder if maybe this switch is anyhow disabling power source to inverter (or something similar). If some of Acer technicians is reading this, I would really like to hear his/her advice. Thanks