SOLVED No Reverb Effect with VHS

[LoserLazer]

Hello everyone,

I completed my build of the VHS pedal and the reverb effect does not work. I suspect I have a bad eeprom but was wondering if there were any other troubleshooting steps I should take.

Audio passes through the board just fine, the switches turn the effects on and off, and the volume and chorus effects work.

Turning the pot of the reverb channel makes no change to the sound.

I verified the FV-1 chip was working by grounding pin 13. This gave the reverb pot some sort of pitch modulation.

The eeprom chip IC2 is getting the right voltage and has continuity to the FV-1.

Is there anything else I should try?

 

[PJS]

My first thought is that the pot is damaged or the pins for it on the FV-1 are not properly soldered. I notice you have soldered the leads to the pots to the eyelets. Although that is not a guarantee to break the pot, it is quite common to damage them this way. Much better to solder to the solder lugs. With the power off check for correct resistance between the outer lugs, and for smooth progression of the resistance between the middle and outer lugs as you turn the pot. I would use the corresponding pads on the board to check. If that all checks out then check the FV-1 soldering. If the chorus pot is working then it is really only pin 20 to worry about.

 

[LoserLazer]

Thank you for the fast reply and spot on troubleshooting. I tested the reverb pot and everything looked good. I tested the chorus pot and it wasn’t working properly. Replacing the chorus pot fixed everything. Thanks for the help!