Alright, time for the next chapter of my MP1 adventure, I've discovered that the unit is unresponsive to midi program changes.
I was originally trying to send program changes via my kemper. After that didn't work I was able to use: https://github.com/gbevin/SendMIDI & https://github.com/gbevin/ReceiveMIDI and verify my cables and kemper side. I can see that the midi thru is indeed working on the MP-1; meaning I'll see the program change come back through. but the unit is not responsive to program changes. I've tried every combination of channels & omni that I can think of too.
I did find this tips sheet here: http://www.marshalljmpmodshop.net/ADA-MP1-troubleshooting-tips-1992.pdf
and I see that I can purchase an 1807 chip from marshalljmp's shop (which I probably will). ....but I want to do my due diligence to make sure this is *the problem* and not a symptom of something else. While tweaking the midi channels, I was able to recreate the last problem I ran into here: http://adadepot.com/index.php?topic=2253.0 I basically locked up the unit and none of the buttons were responsive. This makes me wondering if the problem is beyond the uart chip.
I'm curious if the condenses here is I should just swap the chip or if there's more that should be ruled out. Unfortunately I don't own a scope, just a multi-meter. I'm good w/ an soldering iron, but not at tracing circuits. I fear this diagnostic may be beyond my skill level. Anyway, thanks in advance for any input on this.
Cheers,