Couple broken pedals - Boss, JHS - ideas for fixing

Started by ChrisJoyeMusic, June 15, 2018, 06:51:26 PM

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ChrisJoyeMusic

I bought a handful of broken pedals and want to try repairing them myself with my very limited electrical knowledge.  Again, keep in my I need pretty specific hints, as I don't even know how to read a schematic! (I found the tutorials on here, very cool! Gonna try to learn some)

1) I have a JHS Mini Foot Fuzz. Sounds great. But it only works when engaged. When I bypass the pedal, I get no sound to my amp. Any ideas where and how to fix this? 

2) I have a Boss DD-3 that powers up with Pedal Power Plus 2 or battery (battery removed, generally though).  I do not get any sound out the Output jack. I get dry signal out the Direct Out, though.  This would lead me to replace the Output jack. I only see one wire going to it and the solder joint looks OK, but a little "white" crust around it on the board bottom (residue from iron?), which makes me wonder if they tried this before.

I should mention I have a digital multimeter, but need tips on how to use it for this application.

Thanks!
N00b, aka ChrisJoyeMusic

ElectricDruid

These both sound (on the face of it) like pretty easy fixes. In both cases, I'd be looking for broken wires or joints that have failed.

For (1) you need to follow the clean signal through from the input jack to the bypass switch. Is the pedal true bypass? It'll make it easier to fix if it is, since there'll just be the switch between the input and the output jack.

For (2) it sounds like there's a wire broken off the output jack. Is it a ground wire or a signal wire? Which bit of the jack is the one that's left attached to? The tip? The ring? Once you know that, you know what you're looking for and you can start hunting where it should be attached. Are there any loose wires hanging around anywhere looking like potentially candidates?

HTH,
Tom

ChrisJoyeMusic

Thanks!

JHS
I determined there were TWO wires that were never soldered to the lugs on the switch.  I glossed over this because I didn't think I would see that sort of quality error.  It seems like a big oversight.  I soldered them and the bypass is now working. 

The Boss seems like a trickier issue, and the schematic looks pretty overwhelming.  There is only one wire on the output jack of the Boss, I 'll need to revisit that and try touching up the joints. Not sure if it was supposed to have 2.


ElectricDruid

Quote from: ChrisJoyeMusic on June 20, 2018, 12:56:07 PM
The Boss seems like a trickier issue, and the schematic looks pretty overwhelming.

Yeah, Boss schematics all have that buffered-FET noiseless switching and a discrete flip-flop to run it. It makes the schematic look complicated, but for many purposes it can be ignored. The pop-free switching was a big selling point back in the day.

Quote
There is only one wire on the output jack of the Boss, I 'll need to revisit that and try touching up the joints. Not sure if it was supposed to have 2.

Yes, it was supposed to have two. If that's what the problem is, you won't have to worry too much about the schematic beyond working out whether the wire you've got left is the output signal or the ground.

HTH,
Tom