In some of these pedals the switches have become unreliable. These are similar to those that BOSS uses in the compact pedals, but they were made by the Japanese maker ALPS and have a different size. There is no direct replacement, but with some tricks you can use a tactile switch by Cherry, who use these in their high quality computer keyboards. The Cherry switches are said to work over 100 million times. These should do the job.
Here is the board of my new addition, the Aria ATO-1 Tube Overdrive, still with the original ALPS switch that needed several stomps to activate the effect. Out with it!
Here you can see that the bottom of the ALPS switch is flat whereas the Cherry switch has a hump. Also the metal contacts are positioned differently.
The first step is to drill a hole for that hump of the Cherry switch. 4.5mm is the size that works best and it is recommended to start with a smaller drilling bit.
After twisting and bending the metal contacts a bit, the switch can be set in. For sure you can use additional wire, because the contacts are just long enough to be soldered.
Soldered. As said, you can surely solder longer wires directly to the switch and lead them through the holes. But I think this is sufficient.
I applied a bit of glue to the bottom of the switch so that it will stay in place. This will also reduce the risk of damaging the solder joints.
It will work now, but you will notice that you have to use more force when stepping on the pedal. My solution is to attach two small layers of isolating tape to the treadle part that presses the switch down.
Now your pedal should work properly again.
