This is going to get long, so bear with me. I'm not really sure if this should be in a XP forum or mobo one so both will get it.

The school I work for has 21 old Compaq iPaq desktops. About 1/2 are 500 MHz PIIIs and the other 1/2 are 733 MHz PIIIs. These were donated to the school from a large corporation, and the HDs were wiped clean before we got them. Windows 2000 Pro has been installed on all of them by myself with the intention to then upgrade to XP Pro.

Everything was going great until I went to do the XP upgrade. On the first one, it crashed during the upgrade (I'm not sure when exactly as I was not attending it). When I say crashed, I mean when I turn on the power I don't even get a POST. The power light comes on, but the hard drive light and monitor do not come on at all. No beep codes. Nothing. Tried a different hard drive. Installed 2000 and upgraded to XP. It ran fine for about 1 hour and then without warning it appeared to reboot. After the POST all I had was a black screen with a blinking cursor in the upper left. Once I shut it off and attempted to turn it back on, I was back to a power light with no POST, no HD, and no monitor.

This has now happened on 3 different machines. 2 of them are 500 PIIIs and 1 is a 733. I don't believe the problem is the hard drives as they work fine in other machines. I tried switching out the memory modules thinking they may have gone bad but no luck. I even got desperate enough to replace the RTC battery on the mobo thinking maybe it was that. Nope. The only common denominator seems to be that they have been upgraded to XP as none of the ones running 2000 have done this (yet anyway, I'm holding my breath).

In my 10 years of being a pc tech I have had a load of different problems but never have I had a machine not POST at least to a beep code.

Here is my diagnosis: there is some kind of problem between the BIOS and XP. I cannot find any information on this happening to anyone else or what I should do about it. BIOS flash would be my initial reaction, but these things have no bootable floppy and since they don't POST flashing can't be done anyway.

Does anyone know if I am on the right track or have any better suggestions? This is a BIG problem for us as our whole computer lab is these things (right now running 2000). I hoping it is an XP problem and my 2000s will continue to run fine. I would like though to get the 3 dead ones running reliably again. BTW, I have installed XP SP3 if they run long enough and then they still die. Otherwise, they are XP SP2 and die.

I don't believe the problem is the XP outright. When I put the drives in another system, they work fine and if I put a different drive in the bad system it still doesn't work. I think the problem is that something in XP hoses up the mobo/BIOS somehow. If I remove power from them (i.e. disconnect the power cable) for a long period of time (i.e. days) and then boot them, I can sometimes get a POST and enter the BIOS--but only once, maybe twice. Then I'm back to no POST until power is removed for another few days.

Sorry, I forget to include that. I really have no idea what the model numbers are. There are no model numbers anywhere on the things. All they say is iPaq and give a S/N. I assume the 733s are model P733/810e because that is the only model 733 that HP/Compaq support lists. Not sure on the 500s. These are really just logical guesses as the only pics I see of the iPaqs on the support site are all the same document and not what I have. Ours have no legacy board. They have serial, parallel, and PS2 ports built in with 2 USB ports on the front and none on the back.