[Milsurplus] Help with AN/FRR-59

[Dr Howard L Ritter, Jr]

I need some help from experienced AN/FRR-59 jockeys. I just received an 
'FRR-59 that I bought sight unseen. Although it is inoperative, in 
general it looks in good shape except for what I think is the 
internal-standard module in the upper drawer of the converter blister. 
The 8-wire harness connecting it to the rest of the chassis has been 
disconnected by cutting the wires at the terminals in the subchassis 
and the 3 coax lines have been disconnected. Since the Dzus fasteners 
anchoring the box to the mounting rails (cool construction technique!) 
were not fastened and the top of the subassembly box is missing, I am 
assuming the previous owner found a reason to remove the subchassis, 
although he obviously put it back in place. Anyone know why this might 
have been done? Is it known as a troublesome part? Will the receiver 
function without this module?

In addition, the upper (demodulator) blister isn't powering up, even 
though the lower blister, which gets its power from the upper blister, 
seems to do so properly and the AC power cord is correctly connected to 
the upper blister. The fuses are good. When I remove a fuse and replace 
the fuse cover, the neon telltale does not illuminate, indicating 
absence of power. This is presumably why the receiver isn't working. 
Any suggestions what to check first?

Any suggestions appreciated. This looks like a fascinating piece of 
gear, and I'm looking forward to getting it operational.

Thanks to all,

--howard n7exn