Marshall Artist 4203 reverb not working

[PoPo75]

Hello. I've had an old Marshall Artist 4203 1x12" combo for a number of years. I've always had a problem with the reverb. Back when I was using the amp regularly, like 15 years ago, if you gave the top of the amp a good smack it (the reverb) would turn on. Now that trick has stopped working and I would like to get it back to original working condition. I've had the amp re-tubed recently but the guy never looked at why the reverb was not working. I'm just curious what would cause this?

[52 Bill]

...if you gave the top of the amp a good smack it (the reverb) would turn on. Now that trick has stopped working and I would like to get it back to original working condition.

Most spring reverb problems are mechanical in nature, maybe 80%-90%. Start by checking the cables that connect the amp to the reverb tank and then the tank itself.

The RCA connectors can get corroded or oxidized and stop making contact. Inside the tank there are very small wires that connect the RCA jacks to the input and output coils that can break from flexing too much. Worst case is that one of the two transducer coils has gone bad and the entire tank will need to be replaced.

If the tank and wiring all check out okay, then the problem is inside the amp itself.