Hi
There is sometimes a problem with grease from the shaft of the switch dripping down onto the switch cradles.This is easily fixed by mechanically cleaning the inwards of the switch and does not require soldering.
The switch can be taken apart and cleaned with a dry cloth.
You'll see this with the spring loaded pegs and why the grease could be randomly dripped.
To open the switch untighten the switch from the box and bend the hinges that hold the top metal part from the blue plastic switch house, with a small sharp jewler's screwdriver and make sure to do this over a piece of paper as the inner parts will likely fall out.
Then clean the three metalplates with a dry cloth and spray a little bit of contact spray into the house and let evapourate. Switch can then be assembled back again and mounted into the box.
To put together again first put in the switchplates
(Oh a note on those if you'd like to clean those and don't have acces to a Dremel with a metalbrush you can also use the Jewler's screwdriver edge to sharpen or if you have 'troll wool' that's the kind of steel wool that you clean frying pans with and also make shiny guitarfrets with.........)
then make sure all three black spring loaded pins are inplace in the white cardle and mount the cradle in the slot and then put back the metal pin and the spring and the top part and adjust so all fall in place and press together gently and now you should be able to press the hinges that are on the top metal part to fit into the slots of the bottom blue switching house and press together with the jewler's screwdriver one side at a time and you can use the side of the box to hold one side of the hinge joint while presing the other to make sure that both join snugly. These are soft metal and nylon and there isn't much force needed.This repair is possible without soldering and all wires still connected to the pedal slack and it would take about 4 minutes.
You'll need a Phillips head screwdriver for the bottom screws and a jewlers' flathead for operating on the switch and a wrench to untighten the footswitch
In the top metalpart inside this there is one metalpin that has a flat end and a round end and this should be mounted with the flat end inside the topmetal,
then there's a spring that is coned,this should be mounted with the wide side facing down onto the white nylon part which has a slot for the metal pin and three black springloaded pins one for each metal rocker. Each rocker need to sit in the dedicated slot so that they can flip back and forth.
What makes the switch click are the three rockers snapping in place and what makes the switch spring back is the spring inside the metalpart.
Why this problem occours in the first place
is because inside the switch there are three springloaded pegs that are assembled with grease to hold both the pegs and the springs in the designated slots and the amount of grease used to hold the springs is hardly exact at the switchfactory.
Excess amount of grease eventually gets into the switching mechanism and then causes intermittent to 'open circuit'.
Cleaning the switch ensures that the problem won't come back and it can be done in less than a few minutes if you are skilled and without soldering also there isn't much tension between the metal and the nylon housing and even this can be easily put together.
It looks more difficult than it actually is.
Replacing the switch could ofcourse be done but then you never know if there is excess grease that will eventually drip into the mechanism.....
That said there would be about one out of 50 switches that would have this and one cannot take each one apart but only fix it when it occours while uckily it is very easy.
Swift checking of footswitch with DVM/VOM:
An easy way of checking if there's a problem in the switch is to measure connections the middle row switches between the outer sides so for instance with a three pole you'd have the middle row connecting to the upper row or the lower row from left to right and continuity can be measured with a DVM beaper function within seconds- switch on/off gives then if switch is working properly
As a sidenote
I formerly worked as an airtool/electricaltool mechanic for industry and mines and in view of the sometimes hard circumstances the tools would be used and also sometimes it'd take weeks to get a spare part while service if you knew what you were doing it would be easy.
At your service
BJ