Holy heck. I think I’m looking at a piece of terrible broadcasting history here— the Tektronix RFA400A.
It ran Windows NT Embedded.
It has a dual Pentium Pro Slot 1 400 Mhz backplane PC inside, which does not boot, and chances of finding a replacement are probably zero. I’d guess probably about 31 of these boards were ever made and the other 30 have already been thrown in a Homer Paint Bucket full of acid by some gold scrapper in their backyard.
I’m estimating chances of being able to repair this thing at approximately HELL NO percent. Thankfully we have far better, newer test equipment in place already. YEET!