Display Goes Black After a Couple of Seconds
I had my system running fine on Debian for about a month and a half. Then tonight the display suddenly went black. The system was still running, but my screen was black (though the monitor didn't indicate that it had lost signal). I restarted the computer; it booted through the BIOS and showed me my GRUB menu, but then the display went black again. Shorting the jumper pins to clear CMOS data didn't help; in fact, that made the display go black even sooner. Now, I see my motherboard's BIOS splash screen for a couple of seconds, and the display goes black. I know the system is still booting okay, because I hear the usually noises from the internal speaker. But I now have no visual output.
Could this be an issue with the motherboard or the video card? The board doesn't have onboard video, or else I'd try that. And I don't have any spare boards, video cards, or monitors available to me here. I did try using a D-sub cable instead of DVI-D (my monitor and video card support both), but that was no better. What can I do to try to fix this problem? I really need this computer for schoolwork, so any insight here is appreciated.
Motherboard: MSI 870A-G54
CPU: AMD Athlon II X2 250 (at 3.0 GHz, not overclocked)
Video card: Sapphire 100252HDMI Radeon HD 4550
Monitor: Asus VW195T