SOLVED Troubleshooting an Arachnid

[Bouge]

Hi All,
I've built a few pedals from here, all successfull. So far I've always been able to troubleshoot faults in my builds quickly.
Build #5 seems to be beyond the ability of my usual truobleshooting equip/techniques.

This build is an Arachnid board, which worked fine during testing immediately after first assembly on my workbench, soon after the signal cut out leaving only the clean signal. when I max out the mix pot i get nothing, when I turn it back, the clean signal comes through.
I have traced the entire circuit for correct voltages using a multimeter at all the boards components and am confident the simpler components are doing their jobs. (I also have a functional Arachnid for reference, build #3) I have also swapped the opamp and eeprom chips between those builds and found them to work perfectly.

A quick google search recommends I build an Audio Probe and start poking around the fv-1 circuit, which i'll be trying this afternoon.

Any advice is greatly appreciated, thx.
~Bouge

 

[Bouge]

Solved.

 

[p_wats]

Solved.

Great! What was the issue (in case anyone else has problems down the line)?

 

[Bouge]

Great! What was the issue (in case anyone else has problems down the line)?

The Audio probe I made, along with a few other similar posts in this forum, were very usefull in tracing the cause of my problem.
I traced the signal and realized it was not outputting from the fv-1 (pin 28).
I then tried jumping pin 13 to ground to enable the fv-1's onboard effects and verified signal at pin 28 with my audio probe and it worked.
This led me to the eeprom again. After swapping a few 24lc32a in and out, i realized that the problem had become intermittent, which was an improvment.
At this point some of my build was on breadboard as I had planned a few off board mods, including the eeprom.
I rearranged the cuircuit on the breadboard to use different holes in the board and voila, everything worked great.
It turns out the cheap breadboard I used had worn out contacts where I had the SDA leg of the eeprom, causing the fv-1 to not receive instruction.
It could have been caused by the swapping in and out of IC legs on this particular cheap breadboard, i remember reading warnings to that effect somewhere online a while back.

thx to all the help in this wonderful forum.
~Bouge