Broken Spring Reverb, Could this be the problem?

[hessodreamy]

I've got this fender solid state amp but the reverb doesn't work. You turn the reverb level up and it just hums a bit, but no verb.

Anyway, I opened things up. The cables from the main amp to the spring unit at the bottom of the chassis are ok. I removed the reverb tank and one thing I did notice when I checked inside the spring unit (a simple 3 spring unit, pic attached) is that there's no resistance between the inner and outer lugs of the input socket ie they're connected somehow. Is this right, or does it point to something being shorted?

[Jazz P Bass]

The input coil is generally a lower resistance than the output coil.
I would guess at 200 some ohms for the input.
What reading do you get on the output coil?
The black wire is the ground return wire.
Red is signal.
You must read something between each coils black & red or you have an open circuit.
Sometimes the wire breaks at it enters the coil.
I have peeled back the tape already, found the broken piece & resoldered it.
Sometimes, Not!

[hessodreamy]

I think I understand now. Never looked at these things before.

Basically the resistance I measure across each of the connectors is the impedance of the in/out coils, right? When I said there was no resistance across the input, it was actually about 35 ohms.
And where the output was showing infinite - further inspection shows the coil wire has snapped.

Now let's see if I can get the bugger back on...

[Jazz P Bass]

Reverb Coil Wire

You may find it easier to get a good connection if you gently remove the varnish that is on the wire.
Add a small jumper strand between the broken ends.
Grab a stranded cable (18 ga?) & strip it back You will find the strands work well as jumpers.

[hessodreamy]

Looks like it's screwed. Can't seem to get enough of the wire free to re-solder.
Unless anyone has any tips for this situation it looks like a dead duck.

[hessodreamy]

I'm looking into replacing the tank and I've seen some on eBay. Are they pretty generic or do they need to be matched to the amp?

[bkahuna]

I'm looking into replacing the tank and I've seen some on eBay. Are they pretty generic or do they need to be matched to the amp?

There should be a string of letters and numbers on the other side of the reverb(for example: 8EB2C1B). Just match those to a new one and you'll be set.