Laney VH100R Footswitch problem  [SOLVED]

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Frank Triggs
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Post by Frank Triggs »

Hi, not allowed to post to the switching forum so this one seems appropriate I hope.

My Laney VH100R footswitch when plugged into the amp, causes the amp to constantly change between channel A and B. It flips channels a few times a second.
The amp has 4 channels, or 2 channels with switchable gain stages for each, the footswitches left to right are A Drive, B Drive, Reverb and Channel A/B. With LED's coloured green, red, yellow, red.
Connected to amp with 5-pin DIN cable.

I know for certain the cable is fine, and the amp is fine, as I can use the same cable, plugged into a G-System to change channels on the amp perfectly with the G-System's 2x TRS relays wired into 5-pin adapter socket.

It's only 4 switches and LED's in a metal case. I've re-placed the suspected Channel switch, re-wired it with new hook up wire. Still same problem.

This really has me scratching my head! What can I do?
Music is a sculpture in time and space...

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phatt
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Post by phatt »

You might have the wrong switch polarity.
There are 3 basic possibilities for a switch,
1/ latching (stays on)
2/ momentary,, which have 2 options.

Momentary switching systems are either NC or NO (Normally Closed or Normally Open)
What might work on one piece of equipment may not work on another.

You need to find out what type of switching the Laney needs to work as intended, there is a fair chance the G system is the opposite.

I know with midi keyboards there is often a mode slide switch on the side of the sustain pedal allowing you to swap from NC to NO.
My Korg keyboard goes nuts if I swap the polarity of the pedal switch. :lol:
Phil.

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Frank Triggs
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Post by Frank Triggs »

It's the original Laney FS-4 footswitch supplied with the amp. I bought the amp brand new years ago from Flying Pig when they had their closing down sale.

I've just drawn the guts in a schematic program. It's a bit crude, but all the connections are there. The stomp switches are latching SPST's. The 5pin is supposed to be a round 5 pin DIN socket, but this schematic and pcb program I'm using doesn't have that component. I might have the LED's incorrectly oriented in this pic. But they all light up when on in the footswitch, so they're installed the right way around.
fs4c.jpg
fs4c.jpg (53.53 KiB) Viewed 1784 times
Edit: I might order a new 5 pin DIN socket and replace that.
Gut shot:
WIN_20210518_16_51_18_Pro.jpg
Edit2: Just noticed the yellow and grey(white) are reversed in my drawing, but they're going to correct pins. Just wrong colours.

Cheers.
Music is a sculpture in time and space...

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Frank Triggs
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Post by Frank Triggs »

I soldered a wire between the previously unconnected 5 pin chassis lug (ground) and connected it to pin 3. It now works ok !
Music is a sculpture in time and space...

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Post by [Gringo] »

Just in case you still have the amp/footswitch, could you please confirm that the cable from fs to amp is a 5 wire cable? Got a used one recently and the cable has only 3 wires connected to the inner 3 pins (looks like a midi cable to me), and obviously it's not doing much on two of the switches. Amp switches fine from the front panel. Thanks!

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