I'm fixing a Fender stand alone solid-state reverb for a friend of mine; and while I doubt the problem lies there, it occured to me if I have no idea how to check if the reverb tank is good.  (i.e., bad connections on the drivers or whatever) I can't find much info about the specs for this tank - it's a "XXXX Special Products" tank, (the XXXX is where the company name has worn off - but I assume it's a Gibbs, because it says it's a "subsidary of Hammond Corporation", and it's made in Janesville, so that must be the Gibbs plant, right?  There are numbers stamped on the tank in three places - inside, a "4U1" and a "64063" and on the outside of it, "F191470"  Does anyone know where I can find info on this tank?  I've had no luck.

The circuit looks like a relatively simple build, I'm going to try and make a schematic of it (you know, I wish I had more time - work is killing me) It's an interesting layout - it seems like they used the board for more than one product (maybe a built-in-the-amp reverb as well?) because there a few capacitor components soldered on surface mount style on the back, and there are some spots where the silkscreened component numbering and outlines indicates additional components should go - the wierdest of all being the power transformer.  This unit is set up with a box containing the powersupply, the reverb tank, and the circuit board all seperate.  (the board is mounted by the pots and jacks - the jacks being like the kind they sell at Rat Shack except with slightly longer tabs for connecting, and a small hole cut in the PCB for a the tip to stick through) The power comes in from the wall, goes to the power supply box where it goes to the fuse and the power indicator light - and then goes up to the circuit board where it gets filtered the hits the on/off switch and then bounced back to the power supply box to go to the transformer and then back to the circuit board again - the odd part being that it comes through a hole in the board cut for the same transformer to be board-mounted.  

anyway - blah blah blah - I ramble too much (the wine's fault, I assume.  Which was also DIY, btw) but how does one go about checking the working/nonworking status of a reverb tank?  I'd assume checking the input/output resistances?

Figure out what the impedances should be, and then measure them, I guess :?