Boss Switch

[typethree]

I picked up a Boss RV-3 cheap the other day because of a switching problem, and can't seem to figure it out. When you switch the pedal off, it cuts ALL power to the pedal, works just fine when switched on. I've looked for diagrams, and at other Boss pedals, but am coming up empty. There isn't any real sign of being messed with/re-soldered anywhere either. I'm wondering if it's something simple like bad switch, or a ground wire going somewhere it shouldn't or something in the switching circuit that isn't working right.

[Rixen]

welcome !
Schematic here: http://www.freeinfosociety.com/electronics/schemview.php?id=168

first thing I would check is a short circuit on R39 or R40, because it's an easy test for one fault that would cause that symptom.

[zombiwoof]

I don't know if the Bossarea forum is still around, but they had a procedure in some kind of FAQ section on how to take apart and clean the Boss switches instead of replacing.  Relatively simple as I recall.  Maybe do a search if you think the switch is the problem.
Al

[typethree]

I have replaced the switch and am have still having weird issues. When plugging in a 9v boss adapter the pedal instantly turns on, even with no cables plugged in. When running off a battery, I have to have a cable plugged in to the input for the pedal to operate. When I switch the pedal off, I get a bypassed sound for a few seconds, and then a gated broken sound when the pedal is switched off eventually fading out to no sound after a few more seconds, both off the battery and the 9v adapter. I have checked the switching fets and they seem to be operating correctly. I've checked R39/40 and they also seem to be working correctly. Any idea's on where to go next?

[Ice-9]

When plugging in a 9v boss adapter the pedal instantly turns on, even with no cables plugged in. When running off a battery, I have to have a cable plugged in to the input for the pedal to operate.

That is correct operation.

The other fault needs checked out, when you press the bypass button can you measure the voltage on the 9v lines. does the LED fade out as well or does that stay on when in effect mode ?

[typethree]

I checked a few other Boss pedals, and with the exception of the tuner - none are "on" as soon as you plug in the 9v adapter and all require a cable plugged into the input to turn on after the adapter is plugged in. I have also noticed that I can switch the pedal off and on when touching the correct lead on each fet with the dmm. I don't seem to be able to do that with the RV3, but I'm sort of guessing it to be, q5/6 in not 100% on that. Otherwise the power readings seem to look ok to me on everything I've checked.