RADEON X300 Intermittent Resolution Switching

[fopetesl]

Hardware: ASUS M2V; ATHLON 3500+; 1GB DDR2; 250GB Seagate SATA;
ATI RADEON X300.

I have used the card, (a gift from my son - a gamer), happily for nearly three months without a problem in both XP and LINUX.
The other day in XP the screen went blank (black) and XP eventually rebooted.
After some experiments I discovered in LINUX that the card appears to be randomly switching H & V sync frequencies. In LINUX the desktop blacked out and the monitor came up with

 ... out of range
H:91.2KHz V:170.2Hz

so I switched to a console .. OK screen fine. Switched back to GUI and bingo! Screen back up again.
Had to do this several times then it settled down -- for five hours, yet.
Over the last couple of days the problem got apparently worse sometimes not even able to boot.
I upgraded the X300 drivers - no change.
I unloaded the drivers and am using XP's native drivers without any failures though screen refresh is really poor.
So. Am I looking at an X300 hardware failure? X300 firmware failure?
Motherboard failure?
Any clues, please?

[jimbouk]

Have you got another card or onboard graphics to test the rest of the system with. It does sound like the gfx card is on it's way out but couldn't say for sure. Also do you have another monitor to test incase that one is just getting confused with the input. Don't know anything else to say but test by trial and error!

[fopetesl]

Have you got another card or onboard graphics to test the rest of the system with. It does sound like the gfx card is on it's way out but couldn't say for sure. Also do you have another monitor to test incase that one is just getting confused with the input. Don't know anything else to say but test by trial and error!

No other PCI Express cards unhappily. System won't boot with a standard PCI graphics card so bit stuffed there. Tried another monitor, older, but ran at 800x600 but still came up with the same symptoms. So have ordered a new card, (not ATI), and will see what happens there

[jimbouk]

Does sounds like the card then if a different monitor is having the same trouble at a lower resolution. Good luck with a new card!