I did go through it. The input transformer in this case is loose in the magnets. It gets more heat residing in the bag under the amp output transformer. Over all the condition on the input side wasn't great, the jack was loose and shielding on the cardboard bottom cover was in contact with the spring and transducer. Clearing all that up still didn't revive it.

I went ahead and ordered a 2 spring 4FB3A1B, I liked the idea of a 9FB2A1C but didn't have room for the on edge mounting. A steel guitar forum user has been using those horizontally so it might have been worth a try. We'll see, the longer reverb might be cool, there wasn't a medium with the right impedance ratings in a horizontal mount.

Hello, new member here.
I recently bought a RG/RB 120-115 , one of the later ones with the gray stripe on the front. The spring reverb tank is non functioning on the input side. It is a OC Electronics with 533 in blue ink stamped on the outside and 8428 on the inside under the springs. Does anybody know a equivalent to this long 3 spring pair unit? I've looked at the accutronics codes but am a little suspicious of my ohm reading conversions. Doing the chart it is closest to a 9FB2CB.