I've a K6-II 300mhz system (I want to say the motherboard is a P4B).

It's developed an eccentricity where, after it's been sitting awhile (weeks, even) even though it's plugged in, even though it has a new CMOS battery, even though it doesn't throw a CMOS error, it can't find the IDE hard drive. I've tried a 4gb and a 6gb. I plug the drive stats in manually, still can't find it.

Eventually, with enough screwing around, I usually get it to find the drive (by which time I'm out of time or have found another solution to whatever it was I needed to do).

Could it be the IDE controller going bad on the motherboard, or 2 HDs going bad coincidentally, or maybe a faulty power supply?

Any suggestions on what I could try to troubleshoot the problem?