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
Jack Howarth wrote:
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
There shouldn't be any way to blow up your LCD monitor with a modeline. Sounds like quality problems with the monitors.
-Andy
On Tue, 2006-01-31 at 09:19 -0500, Jack Howarth wrote:
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 can't see how the card could damage a monitor, through your choice of display settings. LCD monitors don't work like CRT ones (with an EHT generated from the horizonal output, so the horizontal output must only run at predetermined frequencies; or for those with independent EHT generation, the same situation applies to only generated horizontal output at predetermined frequencies suitable for the monitor). All that should happen if your had settings miss-set should be no picture or disrupted images.
Shorting out the pins on the video plug to the monitor shouldn't do anything, there's no voltages coming from the monitor to the plug. Broken pins in your cabling could be a reason you have no picture.
If you had a faulty video card, that could cause faults in a monitor, though considering your video card's only going to have the ability to put 5 Volts on a pin, maximum, I'd have thought a monitor wouldn't suffer severe problems if it got 5VDC where it didn't expect it, other than perhaps straight to a ground connection. Perhaps you could consider sending the card back with the monitor. But it does seem like you might be running into bad luck with crap monitors from the supplier.
Did they give you a report on what was really wrong with the previously returned monitor?
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Andy Green -
Jack Howarth -
Tim