@op i think its the mobo issue, NLX models means, the edge of the pcb get all the i/o's like hdd usb floppy lan .... if you mess something on this riser, the mobo may suffer
for the TEK riser who connect the mobo and the power pc interface board, i think the riser for sure pass pci lines between them, but moslty passive in nature, unless you have an added lan connector on it (you will have an phy chip on the riser)
ill add this: i had an tds7404, this one has an Radisys mobo, it was a pain in the @$ to restart it, nvram failure and mobo cmos battery, had to read ton of threads to figure out some vxwork configs
no way to flash the bios
for the Radisys mobo, very very picky on the hardware put on the ide ports, i tried at least 10 slim cd-rw and dvd -rw nothing worked correctly, had a mix of hhd and some worked out ... it would not accept the cd-rom as 1st boot device, while the hdd on the second port worked fine
had to boot "ol Dos" with some usb cd-rom drivers, connected an external usb DVD rom, and managed to get win2k on this sucker
and yes it as TEK markers in it ...
and yes you may get win2k to work on it, forget xp on theses, it will get into a continous reboot ( in my case )
and yes for some os recovery, you have some made with Acronis ... and some cd's will expand acronis in the memory and self install ...
i managed to put 512meg on this mobo, even having the right memory type and speed,
dont forget it need ic's on both sides, it would not accept 2x 256 megs at 100Mhz or 2x 256 megs at 133 Mhz, or standard memory
but strangely 1x 100Mhz and 1x 133Mhz of 256meg size worked fine
and i cranked up the cpu for an celeron SL5XQ 1ghz, i had ordered an celeron 900Mhz too at 100 Mhz FSB
forget the tualatin, they will not work on theses, you can find up to 1.1 1.2 gig cpu at 100Mhz Fsb
get the Intel one or the gateway loll
meanwhile i managed to find some NLX riser board, with standard ide connectors not the 44 pins model, to maybe help in the future some re-installation on the 7404, im still waiting for some ide ssd drive ...
just plug an standard atx psu connect the drives and redo the installation outside the scope