system resets with openbsd flash drive

[Jim Rowan]

Hi,

I'm trying to resurrect some neoware ca22 thinclient boxes, and seeing  
strange behavior I don't know how to interpret.

I have a bootable 5.4 usb stick.   If I put that in the box, right  
after the initial bios boot screen (after it says "via c7 1.0Ghz"),  
the system resets.  This is before it tests the memory or probes for  
devices.   If I go into bios setup, and *then* plug the usb stick in,  
it resets immediately.  If I let it start booting windows xp (which is  
on it's flash DOM), and then plug it in, it continues to boot.

Suspicious that it was the usb drive itself, I tried three separate  
brands.  Same thing.
I put grml on one of them, it boots fine.  I put nanobsd on the same  
one; again boots fine.   With openbsd on the usb drive, and I wipe out  
the beginning of the drive with dd, it then does not reset.

I haven't yet managed to get a dmesg captured, but it's a rather  
unremarkable via c7 motherboard.  I've tried changing all the bios  
settings to the most conservative, disabled everything I can, ... same  
thing.  Oh, and I've tried a different box (I have several of them)  
and a different power supply; neither had any effect.

One of the confusing things is the reset that happens when the usb  
drive is plugged in while in the bios setup...

What can I do next?