Question : Problem: Compaq Presario 1692 laptop monitor flaking out

I am working on a Compaq Presario 1692 laptop w/ Linux (Mepis) and Windows XP (GRUB boot loader).
The laptop's monitor has begun flaking out though and an image will only appears normally when the monitor is open very slightly. When the angle between the laptop's keyboard and the monitor gets larger than, say 30 degrees, the monitor goes black. I can see that there's an image still there but it's VERY faint. Using the Compaq hotkeys to attempt to change screen's brightness has no effect.

This symptom occurs in either operating system and even at the first screen (where the word COMPAQ appears as the laptop first boots). For this reason I am guessing that the problem is physical, not software/OS related.

I have been unable so far to get to the BIOS (F10 key when the computer first boots up?)

Other problematic symptoms: fan in the back no longer spins. Installed Speedfan utility but it doesn't detect any fans, just the harddrive. Recently, the DVD drive only occassionally recognizes CDs (data or music).

With all these problems, I am likely looking at retiring this machine, however, if there are any low-cost solutions/troubleshooting steps that someone might be able to suggest, I am willing to put more time into working on this machine. I feel comfortable opening up the laptop to check out possible hardware issues but would need some guidance about what to look for specifically.

Thanks in advance.

Michael.

Answer : Problem: Compaq Presario 1692 laptop monitor flaking out

The condition you describe is what happens when the back light is out.

The backlight is a cold cathode tube (similar idea to a florescent tube) located behind the 'glass' part of the LCD panel and without it you can't see the image on the screen even if it's there.

It uses high voltage which is provided by the 'inverter' which is a small circuit board that is normally mounted inside the screen down between the hinges.

There are two 'sets' of wires that run through the hinge area.
One is normally a 'ribbon cable' which is the one the image passes through.
The other is typically 2 or 3 normal wires that provide the power to the inverter circuit.
Usually one set of wires goes through one hinge and the other set through the other hinge.

As you open the screen the wires move a little bit.

** I am thinking that the the wires that power the inverter have a physical problem through the hinge area (broken insulation and grounding out, broken wire inside the insulation, loose connection at the end) that causes a loss of power to the inverter as you open the screen.  

The thing to do is open up the laptop to inspect those wires and repair or replace as necessary.

If you have to replace with fresh wire make sure you get wire of the same conductor size and that it's the type of wire that can support being moved often. It's best to find the actual part for the laptop but keep in mind to replace it form end to end the screen will need disassembled too.