HD: gone on POST, there in BIOS

[pjungwirth]

This was almost a question to this forum, but I managed to solve it. Nonetheless, I've gotten so much information from here, I thought I'd post it anyway, in case anyone is interested. It seems rather curious to me!

I just installed a Western Digital WD400BB hard drive (100/ATA 40GB) on an Asus A7M266 motherboard. On POST, the hard drive can't be found, but if I go into the BIOS, the computer is able to detect it eventually. If I boot off a floppy, I have full access to the hard disk.

Everything was connected correctly: I had an 80-wire/40-pin cord with the blue end on the mobo and the black end on the HD. It was set to Master on the primary IDE channel. No Slave drive. The power connection was snug.

It's such a new system, I didn't think the hard drive spin-up delay would be an issue, but I did everything I could to slow down POST anyway, to no avail. The HD still wasn't being seen.

I pulled the drive out of the case and was looking at the top for the geometry specs, since I figured I'd set it up manually rather than use auto-detect. I never did find any geometry information, but I noticed this:

"Most drives are shipped with a jumper as shown above. No need to remove for single drive setting."

"Shown above" means across the bottom master and slave pins. I hadn't noticed that note originally, and I'd automatically set the jumper to Master. I figured I'd give it a shot in the original position, and lo and behold, it detected instantly and booted right off the drive. (I had already installed the OS from floppy and CD-ROM.)

I couldn't find this info anywhere in the troubleshooting section of the PC Guide. Is it a common issue? Setting a single drive to master disables POST's auto-detect? Now, I haven't worked on computer hardware for 5-6 years, but I think I would have remembered this one. Is it not in the troubleshooting section because it's so odd or because it's so standard? (Maybe I should be looking in the general HD info sections, huh?)

Just out of curiosity, I tried the boot again with the jumper completely off, and I got the same instantaneous response: hard drive found, system booted.

What do you all make of that? Am I stating the obvious, or is this something unusual?

(As an aside, if there are any linux gurus out there, does anyone know why when I boot off the disk, Red Hat 7.1 wants to use hda2, which is mounted on / and isn't even bootable according to fdisk, rather than hda1, which is on /boot and is bootable. On a normal boot off the HD, hda1 is used.)

Computers are crazy!

--Paul
~{:-)

[kenja]

"...is this something unusual?" In general, yes. I just wasted most of yesterday thrashing with BIOS, FDISK, Norton Disk Doctor, DLGDIAG (from Western Digital's web site), etc., before finally opening up my case and discovering what you did: jumpering the Master pins does not work when only one drive is on the cable (but it kinda sorta does).

My new WD300AB drive shipped with the jumper in a "park" position, which is electrically the same as no jumper at all. I assumed Western Digital followed the conventional jumper formats as the other brands of hard drives I've dealt with. When we assume, we make an ass of u and me.

[BigBlue66]

Hey,

Yes, this seems to be the case with newer WD harddrives. Not sure why they do it.

Glad you found the problem.

Cheers,

Big Blue 66


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Woe is me.