boot sector f*ed

[Roland Smith]

On Wed, Aug 12, 2009 at 03:54:31PM -0400, PJ wrote:
> Well, I've been looking at the disk(s) and I have found some interesting
> "shei**e" that doesn't make sense.
> 1. The fbsd minimal installation that I had set up for recovery of the
> previous crash does not boot... Now, why in Hades is that? I hadn't
> touched the disk since last using it to look at the corrupted disk
> through an usb connection. The current crashed installetion was done
> afterwards and the only change was in the bios to set the boot disk to
> the new installation. The installation was finally completed with all
> the programs working fine... and then BOOM!
> 2. I tried booting from all the disks on the machine (4 disks) and only
> the current crashed one booted!... so, it's not the boot sector at
> all... something is screwy on this machine; either the motherboard is
> buggered (which I doubt, but not entirely), the disks are finished or
> theres some kind of gremlin lurking in the confines of the box.

This sounds more and more like hardware troubles. 

A few things to check (in order of decreasing likelyness IMHO):
- Cables to the harddisks: Make sure they are properly connected. A machine of
  mine suddenly started getting disk read errors after I put in another
  graphics card. It turned out that the SATA connector to that drive had come
  partially loose.
- Powersupply: check the voltages (preferably under load) with a monitoring
  app like mbmon. If that's not possible, check in the BIOS. A failing
  powersupply can give weird unreproducable errors. If you have ever heard a
  popping noise from the machine it could be a short in the powersupply caused
  by dust. I've seen that fry motherboards.
- PCI cards: check that they are seated properly. Although in this case I'd
  say this seems the least likely.

Roland
-- 
R.F.Smith                                   http://www.xs4all.nl/~rsmith/
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