Well, the saga continues. It doesn't have much practical significance, but its an intellectual challenge, and its driving me crazy!
I have these three Compaqs. They are just about identical. They are all PIIIs, though two have 128Mb and the other 192. That's the only difference.
I installed mandriva 2006 on all three in the same way, using the same boot disk and installing over the net from the same site.
Two of them are sitting next to each other on a table, connected to identical monitors. I have removed the battery on both to reset the bios (necessary to remove password to do the install). I've checked all the settings, and they are all set the same in bios. The only change I made to defaults was to set the time. I've checked that the ethernet chipset is the same, and it is.
On one, the network goes off at keyboard power off, and comes back on at power up from the base unit power switch.
On the other, everything reports fine at startup, but the little light on the built in ethernet port never comes on, and the network is first unavailable, then if you do ifdown eth0 followed by ifup eth0, it shows host unreachable. The light remains off. Then if you do a soft power down, disconnect the power, reconnect the power, the light comes on, boot then causes it to give you the identical messages at startup, but this time it works.
Well, today, on the third one, which also does this, I put in a different pci ethernet card. It worked perfectly. Set it up as eth1, removed the other ethernet, eth0. Soft off, it goes off, restart, it comes back on. The only slight oddity was that it seemed very slow indeed in both printing and accessing the printer's web page. It took several minutes to spool a one page document with a couple of screenshots on, and displaying the printers web page was rather slower than I would have expected over a 100mbps LAN connection. But it worked on the problematic power aspect exactly as it should.
I had the vain hope that maybe it could be something to do with manual addressing, so took in a router and set one of the ones that doesn't work to DCHP, but of course this didn't help. Its before that stage that the ethernet is failing to come up.
Of course, I can just put in a second extra ethernet card in the one that doesn't work, and probably will have to, but its driving me nuts. This should not be possible. Or if it is, there should be some explanation of what is different about the one that works. I guess I can swap the hard drive of the one that works with one that doesn't and see if that makes a difference. I could try installing Debian on another hard drive, and see if that makes any difference.
I just do not want to be intellectually defeated by this!
Any other ideas? Any ideas about anything else one could do to narrow down the problem?
Peter