Can a graphics card kill an LCD display?

Jack Howarth howarth at bromo.msbb.uc.edu
Tue Jan 31 14:19:13 UTC 2006


I have a Fedora Core 4 linux box running the ATI fglrx drivers as packaged by 
livna.org. Today for the second time a Viewsonic VP201S LCD display died on 
this machine when attached via DVI. The machine is configured to run slightly 
below 1600x1200 at 60Hz to avoid sparkling in the graphics when glxgears is 
run. This is done with a modeline of...

ModeLine "1592x1194_60.00" 159.6 1592 1696 1872 2152 1194 1195 1198 1236 -hsync +vsync

I have used the same modeline on other linux boxes with ATI cards without 
problems. The first time the display died the failure occured while I was 
using the machine. The display was fine and then collapsed down into a cloud 
of green pixels for a second and then went black. Viewsonic sent back a unit 
with a different serial number after repair (so I believe it was a replacement 
and not a repair). This unit worked fine for a couple of months until I found 
it the display dead yet again. In both failures, the Viewsonic showed a green 
LED when attached to the Radeon 9600 XT suggesting that it was getting a signal.
However the monitor remained dark. Also detaching the display from the card 
did not bring up the digital signal lost alert on the monitor (however the 
LED does go amber indicating it recognizes loss of signal).

Viewsonic will repair this unit again. However i am very concerned that I have 
had two identical failures on different units. Is it possible for the Radeon 
card to kill a LCD display? I have been told that cards can short and damage 
a LCD but that fact that I see a green lit led on the monitor when attached 
to the 9600's DVI port suggests the signal is getting through but that the 
circuitry that drives the image display of the card is dead. Is it possible 
that a card can randomly freak out and overdrive the display circuitry on a 
DVI connection damaging the display? I thought LCDs were immune to such damage
since they don't use flyback transformers.I am really wondering if I should 
replace this card before I reattach a repaired VP201 again. However the card 
doesn't seem to damage a Dell multisync at the same resolution (although it 
did take a couple months for the repaired/replacement VP201S to die).
                  Thanks in advance for any advice on this.
                                  Jack




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