[sdiy] puff of smoke! (MB-808 build)

[Danjel van Tijn]

So just finished building an MB-808 clone. I have gone through and
tested each section and everything works except for one problem:
At one point I put in the ICs and pots to test the HT section. When I
applied power I saw smoke! I inspected the ICs and it looks like the
TL074 had a crack midway through it. I am not sure if this crack was
there before (but didn't see it) or it was a result of some other
problem.
After replacing the IC there was no more smoke or shorts but that
section of the circuit is simply not working. I have looked at a lot
of the suggested test points and I am only getting sound at one point
(marked in red):
http://eight-oh-eight.org/phpbb2/viewtopic.php?t=141

I can't hear anything from the noise source and nothing from the opamp.

The circuit it actually fairly simple if you look at the schematic.

Any tips for fixing this? I am wondering what could have been damaged....

thanks,

Danjel