On Thu, 01 Feb 2007 13:36:35 GMT, Jethro
<Wilson@somewhere.org> wrote:

>I am at my wit's end with these two machines. One is a Pentium 4 2.4G
>on a ASUS P4B533-VM MOBO, the other an AMD Athlon 64 2.4G on a ASUS
>K8V SE Deluxe MOBO. Both have 640G DDR. Both use the same mouse,
>keyboard, and monitor through my KVM. Both are LAN'ed together via a
>D-Link router. Both have 400W+ PSU's. Both have relatively new HDD's
>as C (boot) drive.

What make model current on these PSU?



>
>I have had this problem before, and often I go several months before
>it happens again, like now. In fact, it happens so often, that I have
>to leave both towers open so as to make it easier for me to deal with
>the problem.
>
>I find that more often than not, when I boot-up either machine, it
>either will not boot up at all or will boot up with a missing drive or
>drives.

What happens, were does it stop when it will not boot up at
all? Do these boards POST particularly fast, fast enough
that the HDDs might not have enough time to get up to speed?



>Both machines are running with two HDDs and one DVD. If it
>boots up and the missing drive is not the C boot drive, like say the
>DVD drive, then I may not notice the missing drive right away, if at
>all.

Check PSU voltages. Recheck bios settings. Check on bios
updates, though it is odd that it is happening to both
systems? Exactly the same situation on both? Exactly same
PSU on both?



>
>I have changed both IDE cabling to new ones, and it is still
>happening. I have changed drive power connectors from the PSU's, by
>adding Y-extenders.
>
>Generally, I can jiggle (or re-seat) just the power connectors for the
>problem drive(s), and the next re-boot will be correct, and stay that
>way for a day or two.

.... then haven't you found the problem?
Use a strong light to inspect the contacts on the drives and
power connectors. Use a fine tool to try to slightly bend
the power plug pins (on the PSU) slightly tighter. If it is
difficult to plug these plugs into (or remove from) the
drives, it is possible to crack a circuit board on them if
there was enough stress, or the board wasn't fastended to
the frame close enough to the power socket. Inspect the
circuit boards too as much as possible if it seems possible.



>
>I have not noticed loss of a drive or drives while running, but once
>in a great while a machine will crash with a black screen or lose its
>mouse/keyboard, so I guess it could be happening, so I can't be sure
>
>I sure would like to try another course of action.
>
>Since this happening on both of my side-by-side machines, I am
>baffled.


Is there anything else common to them perhaps running from
same UPS? I doubt that is the problem but I agree it is
odd, unless these are both using same PSU with some
particular problem (perhaps poor quality molex-clone plugs
based on what you'd written).