Since he says that he is getting inconsistent boot on his friends machine, maybe it's good old SCSI issues? Improper termination or a messed up SCSI configuration can cause lack of boot or random reboots.
Is the active termination jumper on? Try turning it off.
Also if he sent it in to GVP most likely they would have tested SCSI which means they probably had a properly terminated test drive in a known good configuration.
Since it's probably a second hand board and you haven't had it working properly go over every jumper setting.
If you haven't done so, clean the slot connector of the Tekmagic board with some isopropyl alcohol. Just go buy a $3 bottle of 91% Isopropyl Alcohol from the pharmacy and wet a paper tower or some cotton swabs and give the contacts a good rubbing. I bet you'll get plenty of grime off of it.
Cleaning the CPU socket is a little trickier, fold over a paper towel a few times till you get a semi-rigid edge, dip that in the alcohol and try to gently get it in the CPU slot for a few swipes. If you're leaving shreds of paper towel in the slot, you'll need to remove those and you're doing it wrong.
Also start with one stick of RAM or two-if it requires pairs. Then if you get that working add the rest.
