bios randomly fails to detect hard drive

My roommate has been having a problem with her Dell computer. Every so
often when she starts it up, the BIOS fails to detect her harddrive.
She was having this problem before I moved in, but I played around,
mixing and exchanging some of the IDE cables and power cords between
devices, and managed somehow to get it working again. Today however the
problem reoccurred after her computer froze up and she had to restart
it. Twenty minutes later she started it up again and the problem
magically disappeared.

Does anybody know what the problem could be? Hard drive, cables,
motherboard, RAM...?

If you need to know more details of her setup, just ask and I will try
to find out. Thanks a lot.

On Thu, 11 Nov 2004 00:42:52 GMT, Will Rose
wrote:

My roommate has been having a problem with her Dell computer. Every so
often when she starts it up, the BIOS fails to detect her harddrive.
She was having this problem before I moved in, but I played around,
mixing and exchanging some of the IDE cables and power cords between
devices, and managed somehow to get it working again. Today however the
problem reoccurred after her computer froze up and she had to restart
it. Twenty minutes later she started it up again and the problem
magically disappeared.

Does anybody know what the problem could be?

Hard drive,

Possible, run the manufacturer's diagnostics after backing
up the data, if possible.

cables,

Also possible, if wigging around the cables (with system
OFF, THEN powering on) helps, replace the cables.

Take voltage readings at the drive plug and ATX connector
with a multimeter, or at the very least note the voltages in
the bios health screen, IF the bios has this screen enabled
at all.

motherboard, RAM...?

Not so likely to be the motherboard itself, generally if it
were the controller or funciton of rest of system would not
return again, unless there were an unlikley kind of physical
stress, bad solder joint or crack in the circuit board.
These things are not at all likely relative to drive or
cable problems.