Homer J Simpson wrote:

"Lord Valve" wrote in message
...

OK, school-time: what you need is a GC Electronics 9337 "Plastone"
contact burnishing tool.

For cheap contact filing get a diamond nail file from the dollar store.
Power off first.

Too abrasive, and *way* too large for the application.

At less than $2 each, there is no excuse not to have the
correct tool. Intermittent FX loop normalling contacts
are fairly common, especially in guitar amps used
in nightclubs, which are at the mercy of ungodly
amounts of cigarette smoke, theatrical fog, perfume,
dust kicked up by dancers, etc. Additionally, mixing desk
channel and subgroup insert jacks also suffer from dirty
normalling contacts; carrying a few TRS plugs with the
tips wired to the rings is a good idea - but a temporary
fix. Eventually, someone will need to clean them, using
the method I outlined earlier on this thread.

LV