losing my mind over debugging

[iommichild]

Here is the problem-o.  I did some mods on my Boss SD-1 per Monte Allums.  They worked great, sounded great.  However, me being the nutjob I am, I decided to go in poking around, put in a new switch, mosfet clippers, everything.  When I was done, it still sounded great. Then I noticed a strange hum from my amp, I isolated it to this pedal.  I poked around somemore, checking for loose grounds, bad solder joints, the usual. I found nothing. 


Put it back together, no sound on bypass, but there's sound when the effect is on.  Actually, there is sound on bypass, but its that weird bypass buffer sound with the clipping, (which is a standard SD-1 thing, I guess).  And that little bypass sound is super weak, unless I dime my amp volume.  What the hell can the issue be? I double checked all of the mishmash of wires going to the board, no components appear to be loose.  I am known to get.....rough when I'm frustrated -  Is it a bad jack?

Any help in the right direction would be great. I've looked at the schematics, but unfortunately, i am not all that great at interpreting them (ie, which part is the bypass buffer).

[GibsonGM]

Hi Iommi,

Many (all?) Boss pedals use Jfet switching, which is why they have the momentary switch...you're just toggling a flip-flop to switch from bypassed to on.  On the schem it's the "X" shaped array of the 2 JFETs (J201s).   Sounds like something in that area might be fried or solder bridged.   

Using an audio probe to go through the circuit might help you localize where the issue is...just a jack with ground clip and a wire on the tip to probe with...you put a cap (.1uF or larger) on the jack between the jack and wire probe to isolate DC from your amp and clip the ground to your circuit ground at battery -  (sleeve of jack).