Marshall JCM2000 DSL 401 channel switching issue resolved.

[Guitarman53]

How I fixed my MARSHALL JCM2000 DSL combo manual channel switching issue.

PROBLEM: Green LED and therefore "Clean Channel" not operating from front panel switches. (Although OK via foot-switch)

DIAGNOSES: All channels switched via foot-switch so I was doubtful that there was a component issue.
I zoned in on the foot-switch input jack at the rear of the amp.

SOLUTION: Looking at the foot-switch socket, there are 3 spring-metal "clamps" that open to allow contact with the foot-switch plug when it's inserted.
I found that the tip connector (the most innermost "clamp" ) was not springing back hard enough to create an electrical connection when the plug was removed.
So I inserted a plug all the way in, thus opening the tip "clamp" with the tip of the plug. I got a screwdriver and forced/bent the end of the metal clip downwards around the tip of the inserted plug.
Upon removal of the foot-switch plug, I immediately heard a "click" and the front green LED turned on. I then tested the 3 LEDs & channels with a guitar via manual and foot-switch operation.

Fixed!!! Hope this helps someone else.

[Jazz P Bass]

Nice repair.
Thanks for sharing the info.