After a series of power outages, caused by various electricians delving into the wiring entrails of my house, I was disturbed to discover that the web server, crimson, had not re-booted automatically.
When I could get in front of the console, I found the cryptic error
message Invalid electronic serial number, and an indicator
telling me to hit F1 to boot.
Crimson is a Compaq Deskpro 5120, now at least eight years old. I began to suspect that its end was nigh. If I could not rely on crimson rebooting after a power failure, it was time to seek a new server. However, I figured I would try and fix the problem before finally giving it a fond farewell.
Googling for the error message told me that the BIOS looked for a valid system serial number on POST. The serial number is written on a white label on the back of the machine (115/230 in my case), and should also exist as an entry in the BIOS settings. Why had the machine forgotten the serial number? At first I thought the CMOS battery must be shot, but since crimson's time was still correct, that didn't seem likely. Perhaps the various power spikes had caused a BIOS reset or something. Anyway, the serial number can be entered via the BIOS. And how does one enter the BIOS?
On crimson, I couldn't, because entering the BIOS requires a special partition to exist on the hard disk. Crimson has had two new hard drives since I obtained it, so there was no way of entering the BIOS easily.
More advice via Google: Compaq (well, HP) provide a means to create
a floppy that will enter the BIOS if the hard disk partition is not
present. You can download SP4711.EXE from the HP
Support site. This program will create two floppies for you.
And they say that the day of the floppy is over...
On rebooting crimson with the first floppy in place, it did indeed give me screen to change the BIOS. The electronic serial number is entered in the System/Processor settings. Note that I had to enter the number without the "/" (i.e. as 115230), and you have to hit return or the field is not saved. I stored my new BIOS settings and re-booted. No error message, hurrah.
Just to be sure, I took power off the machine for a short while, but it still re-booted normally - no error message and no F1 required. Crimson lives to serve again.
