[xubuntu] edgy upgrade + power failure = unbootable?

[David Armour]

hello,

i upgraded xubuntu dapper to edgy on a previously working 733mhz 20gbHD 
second hand Certified Data tower, and i was just (just!) about to click 
on the 'carry on' button, when power went out. [no, i don't have a ups, 
in part because power service in bc generally is quite reliable.] this 
was also a fresh install, so no data to lose, apart from the immediate 
upgrade.

now, pressing the power button, with or without bootable cd inside, 
displays:
    - screen of POST stuff
        => TAB'd screen of Phoenix Award info:
            * 733Mhz processor;
            * drive listing (20.5Gb/none/cdrom/cdrw);
            * 256 Mb memory]
... and ends with:

Remove disks or other media.
Press any key to restart.

a quick read of pcguide's troubleshooting pages [thanks, btw!] on 
possible causes suggests:
    possible bios failure in part from power failure
    possible hard drive failure, from combination of age and power failure

swapping the hard drive out exceeds my current skill level because the 
inside mounting screw requires moving the motherboard mounting plate out 
of the way, and i'm already exceeding my rated speed, repairperson-wise, 
if you catch my meaning. :c)

    i've got an even-older box with probably even-dodgier components i 
can have a look at, but i'm stretched for cash right now & daddy needs a 
bigger hard drive on the main machine!

    have i just managed to make myself a new doorstop? ideas? any 
response greatly appreciated.