Hey y'all. I bought a YCV40 used off of eBay about a year ago and I still love the thing. But when I bought it, the presence and reverb weren't working. I got the presence to work again with a little bit of effort but I can't figure out the reverb. I took the chassi's out and traced the wire from the reverb into the amp and there seemed to be no nicks in the cord and it was inputted securely.

However, it appears as if there was some water that got on the tank. There's a little rust around the output transducer(right word?) but it doesn't touch it or look like it's effecting it.

At this point I'm totally lost. I don't mind buying a new tank, it'd only run me about 40 bucks shipped. But money's money and if it's an easy fix, that 40 bucks will buy me a Dano Cool Cat! Haha.

Thanks in advance for any help.
Fender USA Standard Strat
1972 Aria "Lawsuit" Les Paul

Marshall JCM 900 Dual Reverb w/Randall cab
Traynor YCV40

Effects: (working on it..)
EHX Holy Grail Reverb
Dunlop Crybaby Wah
1978 MXR Dist.+