FX22 Vibro Thang Debug

[Govmnt_Lacky]

Need an assist. I have a DOD FX22 Vibro Thang that is giving me nothing but static noise on the output. Looked at wiring... no dice. Checked for proper voltages and grounds... all look good.

Schematic:

https://www.dropbox.com/s/bhlvlrxp1mu44tk/FX22.pdf

Here are my voltages:

U1/U2: LM13600 (Numbers in RED are different on U2. All other voltages are same as U1)

1) 1.27
2) 1.10
3) 4.40
4) 4.40
5) 5.58
6) 0
7) 5.58
8] 4.40
9) 4.40 3.23
10) 5.58 4.40
11) 9.5
12) 5.58 4.40
13) 4.40
14) 4.40
15) 1.10
16) 1.27

U4: LM358

1) 2.5 - 5.1
2) 2.5 - 5.1
3) 2.5 - 5.1
4) 0
5) 2.5 - 5.1
6) 2.5 - 5.1
7) 2.5 - 5.1
8] 9.5

So... the voltages all look pretty good to me. My LFO appears to be working. All of these were taken with the effect bypassed and all pots full CCW.

I would audio probe but... I have no idea what to listen for and where to listen for it. Not a lot of experience with these OTAs. Can anyone offer an idea of what to listen for and where?

[stecykmi]

i would start by checking the outputs of each of the ota's (pins 8 & 9) as well as the J201's for the switching - both sides - labelled 2 & 3