Hello,

I have several Comapq Aero Conturas (model 4/33) and a couple of them
have very dim screens. The only way I can see anything is to bring
the contrast all the way down. If I bring it up just a little, the
screen becomes very "washed out".
Is the screen going bad? Is there anything that can be fixed? Perhaps
the backlight? I have read that JKL Components sells backlights for
these, but wanted other opinions before I tear open one of these
machines.


Thanks,

Mike McWhinney
Chief Engineer
elja, Inc.

The easiest way to tell if the backlight is an issue is this:

Turn off the backlights altogether and compare a known-good notebook to a faulty one. You may need a good lamp or sunlight to see what's on the unlit screens. If one is still obviously having problems, you can rule out the backlight.

I would not be surprised if the fault lay in the circuit that drives the LCD. On the older Apple Powerbooks (which I've spent time piecing together), this is a separate board which also contains the brightness/contrast controls.

In my limited experience, where an LCD actually fails, it's due to physical damage, else one of the integral driver ICs has failed, in which case you get a blank vertical bar of dead pixels, terminating at the center of the screen, and it doesn't sound to me like that's what you've got. In instances where I've noticed problems similar to what you describe, swapping the LCD made no diff.

Jeff

On 19 Feb 2004 08:13:22 -0800
eljainc@ameritech.net (Mike McWhinney) wrote: