NOOB_ How to create a short within your PCB?

[Marcseo]

Hi, I am having trouble getting a Big Fluffy Pie to work. The main board is working perfectly but when I added the switch it stopped working. I do get sound when the pedal is bypassed and the LED turns on when engaged. The people from Fuzzdog have suggested the optopuss might be dead so they have told me to try and make a short between the JI and CI pads. I am a noob when it comes to debugging so I don't fully understand what they mean... Is it just adding a resistor leg (or any other sort of jumper) from JI pad to CI pad? Do I need to desolder the cables I have in those pads atm?

Thanks in advance for any info!

[ElectricDruid]

Is it just adding a resistor leg (or any other sort of jumper) from JI pad to CI pad?

Yes, that'd be perfect.

Do I need to desolder the cables I have in those pads atm?

No, you'll need those for the signal to go from the switch to the board to your new short.

I guess that they're telling you to do this to test your switch wiring. If it works and you get sound in both bypass and not-bypass, then you know that the switch wiring is ok. That suggests that there's a problem on the board. If it still doesn't work when the board is shorted out, then there's a problem with your switch wiring somewhere and the board may well be fine.

[Marcseo]

Great!

Thank you so much! 

[Mark Hammer]

I repaired a pedal of mine the other day that provided no output.  It worked before I boxed it up, but not after.  Wha happen?

The circuit was built on perfboard, and fit the 1590B enclosure nicely.  I put some tape on the underside of the backplate so clipped-but-protruding leads on the board wouldn't short out.  So far so good.  Why wasn't it working when the back got attached?  After surgically removing my palm from my face, I realized that the backplate has that ridge that runs around the perimeter inside and along the edge of the enclosure.  The tape I thought would prevent shorting out was doing its job, but it only ran out to the ridge, without covering it.  Leads sitting directly under the ridge were touching it and shorting out.  Because it was perf, that allowed me to relocate a few connections further away from the outside edges of the board, and now it works just fine.

[Marcseo]

Hi, thanks for chiming in. I was testing the pedal with a 1590B opened, so nothing could touch the removable lit.


I have done the short between JI and CI but no I get no signal neither when bypassed or with the pedal on. The LED does turn on, but no signal goes through. After breaking the short I do get my signal back but only when bypassed. I have swapped the diode that works with the LED just in case it was burned or damaged. But still having the same problem. The switch is a very simple design (http://pedalparts.co.uk/docs/OptoPuss.pdf)  not many places it could go wrong. Might buy some spares and redo the whole thing. The main board is working as expected and indeed has an amazing sound