[Techtalk] Hardware issue, probably...

[James Sutherland]

On Mon, 22 Dec 2003 17:15:12 -0500, Raven Alder <raven at oneeyedcrow.net> 
wrote:

> Heya --
>
> 	My sigoth's computer is having display issues at the moment.
> (And he's a digital artist, so you can imagine how well not being able
> to see his screen goes over.)  I'm not the queen of hardware, but I know
> people who are...
>
> 	He's got two hard drives in his box, each with a separate OS
> installed on them, and a sizeable 21" monitor.  Yesterday, the display
> started coming up very very dark.  He set contrast and brightness to
> max, and it's still squinting, what-is-that unusable.  We have removed
> and reloaded the drivers for his graphics card, to no effect.  We have
> swapped out another graphics card for his.  No effect.  We changed out
> the monitor for another known good monitor.  No effect.  Booted into the
> two different operating systems he has on the two different disks.  No
> effect.
>
> 	The dark effect is pretty much immediate, from the initial BIOS
> screen through whatever you do.  It just doesn't look right.  I am now
> thinking that it might be the AGP slot on the motherboard, but as
> there's only one of those and we don't have a spare mobo of the caliber
> he needs around the house, we haven't tried that yet.
>
> 	Before we run out and buy a new motherboard, any ideas on what
> else it could be?  Any other detail I can provide?  Thanks in advance,
> hardware gurus.

You've tried known-good monitors, cables, software and AGP cards? Which
leaves either the motherboard, or power supply (or possibly some other
card doing something stupid?). Do you have a PCI video card around to
try? I've found a couple of machines having what appear to be PSU problems:
the AGP card and motherboard together were drawing too much power,
presumably on the 3.3v line; changing to an old PCI video card (which
uses the 5v line) fixed it.

You said "pretty much immediate" - not quite immediate? Does it come up
as normal, then fade away quickly, when powering up? If you can see well
enough on screen, trying a hardware monitor program (mobo dependent) will
often tell you what the voltage on each line from the PSU really is -
if something is out of spec, it'll be very obvious.

Another, related possibility: dodgy contact on the AGP slot affecting
the power supply to the card? (Try the same card, cable and monitor
in another PC to check that.)


James.