Very Strange Issue

[bjk5959]

I built a three-in-one box with an MXR blue box, Mid-fi peace gun, and Mid-fi random number generator.  Everything worked on first try  .  Went to add a Big Muff tone stack to the blue box, and now not one of the effects work.  I didn't touch the other two circuits. 

Power seems to be fine:  measures 9.4 volts to the circuit. 

LEDs work as expected.

Bypass works fine. 

Tried a different power supply and outlet.

The actual DC jack has been a bit abused, but with the normal voltage readings and LED functionality, it should be fine, shouldn't it?  Wish I had an extra jack to try out.


I can go into way more detail if needed, but just thought this was a weird situation.

[GibsonGM]

Hmm, yes, sounds weird.
But, if you had a good 9V line to the board, and a bad ground from board to chassis...then measured form board to chassis, where you have a GOOD ground at the power supply (that was a mouthful), you would still read 9V.....so, check that some wiring didn't get pulled on when you went inside the box!!

Other possibilities: something shorting in the BMP tone stack...something miswired in a stomp switch...a jack became ungrounded/unconnected...
Try audio probing from the input, see where it leads you...

[jkokura]

It sounds to me like there's a connection to ground also.

Without pictures and debugging info, it will be hard to give you precise help. Check out the debugging thread at the top of this forum and give us the details.

And yes, sometimes you think you didn't do anything to the other circuits, but that doesn't mean that you didn't, it just means you think you didn't.

Jacob

[bjk5959]

Thanks for the direction guys.  I'm willing to spend the time to do the full on debugging report, but thought I'd get a couple ideas from you guys first.  Thanks.