bad opamp in a Mutron Phasor?

[Dr Ron]

I'm having difficulty fixing a Mutron Phasor.
It passes signal, but doesn't phase it, although the sound is lower in volume and a bit scratchy (distorted).

I put in an audio signal from an AM radio and traced it as it moved through the circuit and noticed some oddness in two places.
(using the schematic by Richard Boop -- I can't find a link to it, although I did get it from the web)

IC1 pins 2 and 3 had no signal, although pin 1 (which drives the phase chain) had the signal.
IC4 pins 6 and 7 had the signal with a significant amount of stuff in between (like HF oscillation). pin 5 was fine.
IC4 is the last opamp in the phase chain with pin 7 going to the feedback pot.

Would IC4 be the first one to replace?

Or, is it not an opamp issue?
Usually opamps go bad by showing one of the PS rails.

Any help would be greatly appreciated!

Here's a schematic that's hard to read
http://www.sonicurbs.com/mutron2/schem.jpg

[Gus]

First thing you do with Mutron phasers is check/ resolder all the connections on the PCB and pots also check the wires are not broken inside the covering with a DMM set to ohms.

I have "fixed" two Mutron phasers by just resoldeing some bad connections.

After that, troubleshoot if it is not working

[Dr Ron]

I've re-soldered all the connections several times (this morning with a new iron) and the same problem persists.

IC1 pins 2 and 3 are zero signal even at the highest scope sensitivity.
I checked the resistance and they seem to be fine.

I'm not sure what's going on with these signals - it just doesn't look like a bad opamp to me.

Here's the correct schematic
http://www.aronnelson.com/gallery/main.php/v/RLBJR65/Mu-Tron+Phasor+II+pg1.GIF.html

[Dr Ron]

Fixed!

It turned out that a big solder blob to the feedback pot was two separate traces.
(I'm pretty certain it was someone else that did it.)

BTW
The Circuit Specialist in Tempe have an awesome deal on a solder station (about $50 for the CS-1 and a free DMM)