Express 5:50 Reverb

[JjPpMm]

Hello all.

Purchased a new to me express 5:50 2x12. When it arrived the reverb was not working.

I have:
Tried both channels
Unplugged the footswitch
Switched out tube 5
Tried new rca cables to and from tank
Ordered a new tank and installed it
* if I shake the tank I get the slightest spring rumble.

Still no reverb. Any ideas or experiences you all have had that can help me figure out what I am looking at?

I’m pretty handy with this stuff but do not want to venture into the unit unless I know what exactly needs repair.

Any ideas?

Love the sound of the amp but totally bummed at this point.

Thanks in advance.

 

[user 21540]

Looked up scenario with other Mesa amps. This is a Mark V but they went through all checks you have done:

https://boogieforum.com/threads/mark-v-combo-reverb-not-working.72298/

 

[JjPpMm]

UPDATE: Took the amp to an authorized Boogie repair shop.
Needed 2 FETs replaced. Under $100 to replace and check all parts and solder connections….all tuned it up and sounding awesome!
Working like a charm now.

 

[Rob Snelders]

UPDATE: Took the amp to an authorized Boogie repair shop.
Needed 2 FETs replaced. Under $100 to replace and check all parts and solder connections….all tuned it up and sounding awesome!
Working like a charm now.

What FETs needed replacement (for future reference)?
By any chance got your hand on any details on the Reverb circuitry?

 

[Alan Harper]

I had a problem with the F50 and the reverb not working. It all came down to the smaller plug that goes into the base of the chassis. The connection was intermittent. A dab of solder did the trick.