Prophet 5 Rev 3.2 LFO failure

The LFO on my Prophet 5 has stopped functioning. When I set the mid wheel fully to LFO, and select any of the routings (OSCA, OSCB, PWMA, PWMB, Filter), then slide the mod wheel up, it just pitch bends (if on an OSC routing) or just opens the filter (on filter routing). The FLO rate and wave shape buttons have no effect. The pitch bend wheel works fine.

I did take a 3340 chip from the voice board and swapped it into the 3340 for the LFO on the digital board, and the issue remained, so its doesn’t appear to be the LFO chip itself. Maybe it’s an op amp?

I don’t even know where to begin for further troubleshooting as I’m a novice tech at best (haven’t ever even used a scope). Any assistance would be appreciated!