momentary switch doesn't work

[taku0319]

Hi,

Today I got a stompbox as a junk

- On / Off foot switch does not work.

I would be happy if you could give me some advice on how to solve this problem.

[composition4]

Change the 47k resistor to a 10uH inductor, and omit D81. If that doesn't help we might need some more detail, such as what pedal you're talking about and exactly how it doesn't work.

[GGBB]

There's a sticky post in this board (Building your own stompbox) entitled "DEBUGGING - What to do when it doesn't work". Follow the instructions there. Since you didn't build the pedal, some of it will not apply, but try to post answers for as much as you can.

[Rob Strand]

A good place to start is to work out if it's only the switch or a problem with the electronics.

By momentary I'm assume the thing has JFET switching.

A simple method is to:
- check the switch contact are closing at all using a multimeter.

- check the electronics are working by touching  switch terminals with a piece of wire to see if the switching works.
  (slightly better is to temporarily wire another switch in parallel with the existing one.)

There's a case where the switch is closing and the electronics are working but the thing as a whole still
doesn't work.  This is often the case when the switch is old and is bouncing.   Often the switch will
have a small capacitor (1n to 10n) across the contacts, located on the PCB.  Increasing the cap value
to say 47n can often make it work again.

[ElectricDruid]

By momentary I'm assume the thing has JFET switching.

OP didn't actually say momentary, Rob.

I think we need more facts! Like, lots more.

[Rob Strand]

OP didn't actually say momentary, Rob.

I think we need more facts! Like, lots more.

The post title says momentary, but it's still not 100% clear.
Hopefully, the OP can fill in the details.

[ElectricDruid]

OP didn't actually say momentary, Rob.

I think we need more facts! Like, lots more.

The post title says momentary, but it's still not 100% clear.

Ah, so it does. Sorry. I was literally "missing the bigger picture".

Hopefully, the OP can fill in the details.

Indeed.