Sudden problems with Arachnid effect selection (is my rotary switch on the fritz?)

[p_wats]

I'm suddenly having issues selecting patches in one of my Arachnid builds from last year (build thread here). It's been working fine for almost a year, but now seems wonky, as it no longer reliably changes from the first patch. If I apply pressure or wiggle the rotary knob just right it will work. Once I get a patch selected it will stay unless I jostle the rotary knob, then it reverts back to the 1st patch.

This makes me think it's a mechanical issue with the rotary switch itself. I re-flowed the solder joints for the rotary switch, just to be sure and also switched out the eeprom, but no luck.

Has anyone had an issue like this before? I'm somewhat hoping it's not the switch, as it would be a real pain to replace. Open to suggestions!

 

[p_wats]

@PedalPCB have you ever had any similar issues with a rotary switch or any ideas if there's something else I can try before swapping it for a new one?

 

[Robert]

This is the first I've heard of mechanical issues with the rotary switches, but that's definitely what it sounds like.

When it reverts back to Patch #0, does wiggling the switch bring it back to the selected patch?

Turn the rotary to patch #0 then use a jumper wire to short the center pin to each of the outer pins one at a time... If it switches properly you can be fairly certain it's the rotary switch.

It shouldn't be too terribly hard to replace, I would remove the board from the PCB and just clip the outer ring of pins with diagonal cutters so you only have to try to desolder the center pin. (1 pin is much easier than 9 pins)

After that, just remove the pin remnants from the PCB one at a time.

 

[p_wats]

This is the first I've heard of mechanical issues with the rotary switches, but that's definitely what it sounds like.

When it reverts back to Patch #0, does wiggling the switch bring it back to the selected patch?

Turn the rotary to patch #0 then use a jumper wire to short the center pin to each of the outer pins one at a time... If it switches properly you can be fairly certain it's the rotary switch.

It shouldn't be too terribly hard to replace, I would remove the board from the PCB and just clip the outer ring of pins with diagonal cutters so you only have to try to desolder the center pin. (1 pin is much easier than 9 pins)

After that, just remove the pin remnants from the PCB one at a time.

Thanks! I'll give that a try tonight.

Wiggling the switch does bring it back to the selected patch (and I can sometimes get it to stay there if I apply pressure for a bit).

The biggest hassle will be getting the board out of the box and back in neatly, but not the end of the world.

Unfortunately there doesn't seem to be a Canadian source for these rotary switches, so looks like I'll have to put an order together to justify shipping (blessing and a curse, really )

 

[Nostradoomus]

Unfortunately there doesn't seem to be a Canadian source for these rotary switches, so looks like I'll have to put an order together to justify shipping (blessing and a curse, really )

Mini 8-Way Rotary Selector Switch - SP8T

When you need a lot of options, you need a Mini 8-Way Rotary Selector Switch. This is basically a single-pole to 8-throw switch. As you rotate the knob around, the middle pin will make contact with each of the outer pins. Rotary switches are very simple to use and are also nice and compact. This...

elmwoodelectronics.ca

and

https://www.robotshop.com/ca/en/mini-8-way-rotary-selector-switch-sp8t.html

 

[p_wats]

Mini 8-Way Rotary Selector Switch - SP8T

When you need a lot of options, you need a Mini 8-Way Rotary Selector Switch. This is basically a single-pole to 8-throw switch. As you rotate the knob around, the middle pin will make contact with each of the outer pins. Rotary switches are very simple to use and are also nice and compact. This...

elmwoodelectronics.ca

and

https://www.robotshop.com/ca/en/mini-8-way-rotary-selector-switch-sp8t.html

Thanks. I always forget about those guys...maybe because they rarely have stock. The former has a few but is double the price (good old CAD currency exchange plus markup) and the latter has none and works out the same as PedalPCB after shipping costs anyway.

@PedalPCB any idea when you'll have stock again? Not in a rush.

 

[Robert]

They're on the way, I suspect they should be here some time in the next week.

 

[p_wats]

They're on the way, I suspect they should be here some time in the next week.

Excellent. Thanks! Confirmed via jumpering that it does appear to be the switch itself. I'll start thinking about other things I may want to order.

 

[p_wats]

Wanted to reply to this thread to say the above advice for removing the broken switch worked. Took me a while to make the time, but it was easier than I expected to remove it. Just waiting on new stock in the switches now.

 

[Many__Of__Horror]

I've just come up against the same potential issue. Sticks on the first patch unless i push down the switch with my finger. As soon as I let go it reverts back to the first patch again.

 

[p_wats]

I've just come up against the same potential issue. Sticks on the first patch unless i push down the switch with my finger. As soon as I let go it reverts back to the first patch again.

That's too bad. Sounds similar to my issue.

Did you try this to be sure?

Turn the rotary to patch #0 then use a jumper wire to short the center pin to each of the outer pins one at a time... If it switches properly you can be fairly certain it's the rotary switch.

 

[p_wats]

Now hopefully @PedalPCB gets stock in the switches soon (seems other folks are out too).

 

[zgrav]

if we start seeing more durability issues with the rotary switches, it it may turn out that using three toggle switches as shown on the fv-1 datasheet turns out to be a more reliable solution for program switching.

 

[p_wats]

if we start seeing more durability issues with the rotary switches, it it may turn out that using three toggle switches as shown on the fv-1 datasheet turns out to be a more reliable solution for program switching.

I was fine with the regular pot for switching as used in the 2018 boards, which I've never had an issue with. That said, switching to the right patch is definitely easier with a rotary or toggle.

 

[Many__Of__Horror]

That's too bad. Sounds similar to my issue.

Did you try this to be sure?

I did try that, it certainly changes the effect. Though I am not even certain I am even getting the effects out of the eprom. How many effects does the FV-1 carry? I'll continue to look through it when I get a chnace & don't have kids running around everywhere

 

[phi1]

Search fv-1 datasheet for a list of the internal fv-1 patches.

 

[Many__Of__Horror]

Search fv-1 datasheet for a list of the internal fv-1 patches.

8

 

[Many__Of__Horror]

That's too bad. Sounds similar to my issue.

Did you try this to be sure?

Just got a new batch of switches, tested them before replacing and that fixed the probelm.

 

[falzhobel]

I've got one bad 8 position rotary switch. There was space between the rotary shaft and the base. Be aware and check yours before installation. That's quite some pain to remove and replace.