Boss OC-2 octave Down 1 not working

[garfo]

I got a Boss OC-2 that was in a very bad shape full of rust and solders gone pretty bad.
Anyway, I plugged in the pedal before anything else and it works. Octave two and direct signal work, is just octave one that is not working.
I've gone through the pots and the bad solders and nothing changed. Gone through the IC's resoldering and nothing. There is still no First Octave Down on this damn circuit.
Anyone with any in-depth to where I should be looking at to find the problem?

Taking IC4 out stopped Octave Down 2 from working which I assume they are sharing the same opamp.
I'm very lost and since I don't have a sound probe I can't really follow the path and find the faulty component.

Hope someone could help.
UPdate:
I took out BA634 and the pedal still works exactly in the same manner.
Could it be that this is the faulty IC since Direct output and Octave 2 still work and Octave 1 doesn't!?



I took the readings for all the IC's:

IC1: TL022
1- 9.56
2- 9.56
3- 9.19
4- 9.63
5- 9.20
6- 9.20
7- 9.20
8- 9.63

IC-2 TL022
1- 9.04
2- 9.19
3- 9.20
4- 9.63
5- 9.21
6- 9.19
7- 8.91
8- 9.63

IC3 TL022
1- 9.04
2- 9.21
3- 9.20
4- 9.63
5- 9.21
6- 9.20
7- 8.92
8- 9.63

IC4 TL022
1- 9.56
2- 9.56
3- 9.21
4- 9.63
5- 9.20
6- 9.18
7- 9.18
8- 9.63

IC5 TL022
1- 9.53
2- 9.56
3- 9.63
4- 9.62
5- 9.62
6- 9.56
7- 9.53
8- 9.63

IC6 BA634
1- 9.16
2- 9.17
3- 9.62
4- 9.63
5- 9.63

IC7 MN4013B
1- 9.11
2- 9.15
3- 9.11
4- 9.62
5- 9.15
6- 9.62
7- 9.62
8- 9.05
9- 9.62
10- 9.05
11- 9.62
12- 9.11
13- 9.12
14- 9.62

[reddesert]

Those voltages don't seem right. For a 9V powered pedal, you should see about 0V on the ground pin, 9V on the +voltage supply pin, and the other pins of an op-amp should show a DC voltage that is somewhere between 0 and 9, typically around 4-5V but it can vary. The MN4013 cmos IC can be somewhat different, but again, the voltages shouldn't all be +9.

[garfo]

Those voltages don't seem right. For a 9V powered pedal, you should see about 0V on the ground pin, 9V on the +voltage supply pin, and the other pins of an op-amp should show a DC voltage that is somewhere between 0 and 9, typically around 4-5V but it can vary. The MN4013 cmos IC can be somewhat different, but again, the voltages shouldn't all be +9.

I found out what the problem was and despite the weird voltages, the pedal is now working fine. It was one of the traces on the pcb that was corroded and I did a bypass wiring.
All works fine now.