Still not receiving MIDI

[Beethovenboy]

I've had my unit for a couple years now, before v2 I think, SN ATM-13-01-0059 and haven't had any problems with it until today. It won't receive any MIDI messages and I've changed the MIDI channel multiple times (via the YT tutorial). I've never hacked it. Makes noise when I push the 2nd rotary knob but just won't receive MIDI notes. Any suggestions? Is there are simple factory reset I can do? Any help would be greatly appreciated as I love this unit!

[paulsoulsby]

Just to confirm - the unit has stopped receiving MIDI upon booting up?  You've not just done a software upload?  This is very strange.  You've checked that other synths can receive the MIDI signal?  Checked programmer switch is to the right (when viewed from above)?  Switch it a couple of times to make sure it's all the way to the right.
I'll start with the obvious ones first before going deeper!