Neutron problems.

[jrc4558]

Hi forum!
I'm having really hard time debugging a Neutron I built. Its hooked up as per schematic (non-tru bypass way). the "bypass" setting is ok, but the "effect" setting is hell.
Symptoms:
a)very quiet
b)very distorted (almost like an open-loop opamp clipping, only there's no open loop, i checked and am 99.(9)% sure)
c)works only if the switch is in low-pass mode. all other settings - no sound at all.
All ICs are receiveing power and there's no short to either rail.
What could be the problem, just by the sound of it?
I suspected that there's no contact between input and the first opamp, buth how then do I have 'some' signal coming out of it, and the bypass mode is fully functional too.
Anyway, to spare you all my "analysis", I need your help gentlemen. Someone must hve built this beast before, meybe you could help me debug it.
Thanks in advance!

[Aharon]

I know you are an experienced builder so you probably checked for solder bridges and wrong value resistors.
I would check the optos,that's the weakest link and they are known for failing often.
Aharon

[R.G.]

I've done a lot of debugging.

The reason that "What to do when it doesn't work" came so easily to me (I typed it out in one pass, only checked spelling) is that it's always the way to start. Whenever I have a bug in a pedal, that's what I do to find it. I find that when I skip that stage, I tend to miss things that would be simple to fix.

It would be good for you in terms of learning debugging as well as helping us help you if you'd post that information. It's possible that it won't help, but I find very few times that it doesn't.

[jrc4558]

I didnt have the checklist with me to do a complete "checkup".
I will do it next time Im i nthe studio, where the thing is right now.
Thank you gentlemen! Stand by for updates.