Majestic model 90B....no audio

[rca2000]

I have to restore(electronically) a Majestic radio model # 90B. This is a VERY heavily made radio!! 16GA metal all over the thing. Anyway...It seems to be a TRF set. 4 or 5 '27 tubes, a pair of 45 outs and an 80 rect. Tere are NO normal types of capacitors in this set, all are VERY large, oil-types or such. The power supply is mainly choke-filters, with a couple of low-value caps-2-4UF in a "pi type" filter, ALL in metal boxes.

This is NOT my radio I am fixing it for a friend's boss--who "wants it fixed" and pretty much "no matter what". It was his fathers radio or such, and he does NOT want it "modded" or "rigged" with some sort of "hidden SS radio" taking place of the original 1930 circuitry. He wants it done RIGHT--and I am trying to help that get done.

I looked it it yesterday. I seem to be getting plenty of B+, over 350 to the plates of the 45 tubes, and around 55 or so on each side of the filaments to ground. NOTHING on the grids--is this normal?? I have a transformer coupled amp here--the grids of the 45" go to the input tranny, and it is driven by a '27. I CAN get weak audio, if I inject it at the plate of the 27 from an external (isolated for safety, even though the radio is "cold"), source....but I get NOTHING if I try and inject audio at the grid of the '27 driver tube. I get weak, slightly bassier audio on the cathode of this tube, and this had about 25V. or so on it....--but again, NOTHING from the grid, and NO voltage there either!! The driver tranny SEEMS to be good, ohm-wise. The ONLY schematic I can get is VERY poor, with NO voltage readings or such. I have to go "by instinct" on this so far. I do NOT feel I am getting proper filtering, since if I put extra filtering on the b+ line right out of the 80, say, a 22/450v. cap it WILL raise the B+ to about 500 volts there. But it does NOT "change anything" as far as the operation goes. I suspect an open resistor or coil, one of the big" copper colored can's, under the chassis, probably. I ran out of time, having to remove that big metal shield over the tuning cap, to get to the coil leads to check them, and the one I THINK goes to the grid of the driver tube shows to be SHORTED, and is NOT so in the schematic!! There is a cap and resistor to ground here.

SO anyway....am I on the "right track" here--suspecting that I SHOULD be able to inject a signal into the grid of the driver-and get DECENT audio out of the speaker?? a pair of P-P 45's should give GOOD, POWERFUL sound, if they are working right, true?? And shouldn't there be some negative voltage on the grid of the '27 driver tube??

Any help is appreciated.