Footswtich to FSM 432 not working

I have a Grandmeister 40 amp with the FSM floorboard, connected via a 7-pin MIDI cable. Works perfectly for all my stored presets. I recently added some pedals to the effects loop, including a looper, and want to setup an external switch to turn on/off the effects loop (MIDI parameter 55).

I purchased the Orange single switch and connected it via a TS patch cable to port 1 on the FSM. I followed the programming to set port 1 to MIDI parameter 55. The switch lights up when I engage it but nothing changes at the amp. I also tried port 2 on the FSM with no luck.

Did I miss a step?

Hi Speedlude.

I've looked at the Orange FS1 and it looks like it is a standard series LED and switch setup so it should work with the FSM432 and H&K amps to do what you want.  I have used a cheap Thomann FS1 in my FSM432 with my GM36 to do just what you are trying to and it does work.  You could just check simply by setting the amp and FSM up, unplugging the FS1 from its cable leaving the cable in place in the FSM432 and just shorting out the jack plug tip and sleeve terminals on the exposed end of the cable with anything metallic.  That is all the switch inside does so when you short it you should see your amp respond just as when you press the switch.  If that doesn't work then we know there is a problem in the setup somewhere other than the switch.  To be really certain there is no hardware fault you could even check this with another patch cable in the FSM432 and short its plug to rule out the cable as well.

Firstly, (this is a no brainer but needs to be asked to rule it out), while the amp won't respond to that switch does it control the other normal functions as it should?  Asking that might seem to be pretty much a waste of time but it should be clarified before we continue.

Then we should try to programme the switch from scratch again.  I know the manual tells you this clearly but different wording might just get past a misinterpreted instruction.

1) For Control1, hold down Tap + D buttons together.  The display should change to show the current control number allocation.  (I believe the factory default is 7).  The dot behind the right hand digit (the 7) should start flashing to show you are in programme mode for Control1.

2) Use the Up and Down buttons to increase the controller code to 55 for the Fx Loop On/Off function.

3) Finish by storing the new code and exiting programme mode by pressing the D button (without the Tap).

4) Press Tap + D a second time and check the code is now stored correctly and showing as 55.

5) Press only the D button to exit programme mode for the second time.

That should set you up and check that it has taken correctly.  Your GM40D should not have a problem with this type of use, it is compatible with the FSM432 so you are absolutely correct to do it.  I can only think there may be a problem with either the switch itself (unlikely) or the patch cable may be faulty (not too common but possible).  Other than that it should be down to the procedure you followed which may have been wrong in some way.  Try the "jack plug short" test, it is pretty much effort free to try it first, then try programming it again from my instructions just to check.  These should be just the same as the manual but who knows?

Thanks for the tip about testing it with just the cable. The cable and switch are brand new so we will see.