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Spontaneous reboot

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New Member
Mar 13, 2001
Ok, I'm now a spontaneous reboot sufferer. I have a problem with my system (listed below) in that when I am playing games, it will spontaneously reboot. (and measuring temperatures it is sitting right about 45C at the processor, and ambient is 25C) I tried changing the power supplies, As the Motherboard can take both ATX or AT Power supplies, I tried two ATX ones, then concerned the switch through the motherboard was the problem I tried an AT one, to remove the motherboard switching from the loop (not positive that this succeeds in doing that). Anyway, has anyone else had this kind of difficulty? What types of problems cause spontaneous reboots, and are they solvable?

My system is:

Asus P5A-B Motherboard @100MHz FSB
K6-2 533@550MHz
Viper V770 (TnT2 Chipset)
Soundblaster Live! PCI sound card
3Com Etherlink 3 NIC
30Gb Western Digital HD


Particle Man
Sig-Less Wonderboy
I have seen this happen with flaky ram myself. If available, try some different ram...even maybe 64 mb for a test.
the power supply may be failing and that might be the only sign its giving you right now.......a failing power supply can cause spontaneous rebooting...they are cheap, so try replacing that frist.
I agree that it might be the psu, as I suffered spontaneous reboots in games with my 250W psu, and all that disappeared when I upgraded to a 300W (GFDRR, athlon 750 at that point). Sounds as though you've ruled out the psu though, and it could be any one of a number of things - RAM and mobo most likely I reckon.
It may be that the chip just doesn't want any of it whatsoever. I know it's only 17Mhz but stranger things have happened with K6-2's.

The plan was never to make them at anything over 450Mhz anyway!!!

Other than that - is the I/O voltage reading high enough (3.5v is always quite healthy) That may resolve a power trip issue.

Is the RAM PC100 CAS 2?? Is it set up correctly ? Bad memory timings can kill a PC.
Ok, As it turned out it was the Video card. However this brings up an important point. I was fairly certain that the video card was not overclocked. The P5A-B motherboard supports a 100MHz FSB, so the PCI and AGP speeds are still 66 and 33MHz.

Although it sounded like a PSU problem (was my first suspect, since it sounded like the switching was taking place there) I tried two ATX 250W PSU's and a 145W AT PSU with the board. (Also logically since I am only running one hard drive, and the motherboard with it, any PSU should be able to supply that much power.)

The ram has worked well in a couple other boards at 100MHz, but it doesn't actually say anything so it probably isn't PC100 or even CAS2 (was from before I knew the difference).

In any case, it appears that a change of video cards solved the problem. Just my best guess as to what has happened is that the card. (Diamond Viper V770) has been running too hot for approximatly a year in another computer, and has degraded. (No overclocking, just poor design. Apparently the manufacturer needed to spec a fan in for thier heat sink) If anyone else is running these even at regular speeds I would suggest a fan. Other than this I really enjoyed the card, and I'll miss it... <smile>

So, can just about anything failing cause a spontaneous reboot? (never encountered this before, I was expecting most failures to just cause the computer to freeze)