If anyone needs to replace a defective part in their 53310a, send me a PM. I acquired four of these MDAs at auction a couple of years ago, sold one and kept two. Out of the four units, one had been cannibalized for its display PCB but was otherwise OK. I searched for a replacement without success, and at this point prices for complete units are so low that it's not worth fixing/shipping a full analyzer anyway. So, time to part it out. Forum members with a good story may get a special price
Edit... This was a rather strange unit, originally built with option 031 but later with that option deleted, yet some (all?) of the hardware left inside. Boards / part numbers available:
53310-60007 A1 (main board with extended memory)
53310-69002 A2 (input) somewhat inexplicably with four BNC connectors but not the part number of an option 030 or 031 A2 board
53310-60017 A3 (CPU)
53310-60014 A12 (LO)
CRT, front panel, back panel may try to sell as a single "carcass".