Dave Smith Instruments SYNTHESIZERS

This is one of those cases where a problem came and then solved itself
somewhat randomly, leaving me none the wiser. Here's the deal:

I turned on my mono evolver after about three days of not using it and
hooked it up to my midi keyboard. But when I pressed the keys, nothing
triggered. I know the evolver was receiving midi because the midi
indicator light would flash as normal. I couldn't get the evolver to
respond to note-ons or CCs. I checked midi channels, triggering
setups, and everything else on the evolver concerning midi. I even
tried to have it send midi to itself via the sequencer, and that
didn't work. I opened the VCA and sure enough it made noise as it
should, just with no triggering.

I left it for a day, tried everything again, and still got nothing.
Then, out of frustration, I started pressing buttons. I randomly
pressed buttons 1 & 5 at the same time, and the lcd started counting
down from 4. At the end of the countdown, everything worked again! So
what the heck happened? Can anyone explain what caused the initial
problem and what exactly my solution did to fix it?

I guess all's well that ends well, but I'm still curious about my
evolver's peculiar behavior.

Thanks in advance for any info.