Let me just preface this by saying that I think I have this sorted.
I thought I would post the experience in case anyone else has the same issue and freaks out about it as much as I did.
I have a stock mp1 with a new SS tube board and I have done the noise mod. This is one of the early, early models.
My input jack was starting to get crackly and intermittent. At the last gig we played (makes it sound like we do a lot doesn't it?) I had to use tape to hold the lead so that the input socket wouldn't crap out on me.
So I ordered the rear jack mod kit, battery kit and a few other pots and sockets from mjmp. On Monday I went to rnolan's house to use his soldering/desoldering kit to do some of these mods. I have to say that it all went very smoothly. I think I only swore once and that was when I realised that I had installed the new output volume pot with the nut still wound on.
Started with the rear jack mod. Went like clock work. Did the battery while I was still in there. I reloaded the factory presets and tested it. Sounded great. We noticed that the output volume pot was not as smooth as it should have been, so I went back in and swapped it. Got it all back together and it sounded better than good. It sounded better than it had since I can remember. I remember that after the noise mod, I was a little disappointed that it was still a bit noisy. Must have been the jack and the output pot.
When I got home, I reloaded my presets that I had studiously saved using a midi program before going to Richard's place. Well, it all just fell apart. The programs were either weren't there or they we sounding strange. When I used the buttons on the front to change back to the factory presets to just check that they were still OK, the display started flickering like a strobe light and not responding. Redid all of the above several times and got similar results. I assumed that I must have damaged the front panel circuitry when I was trying to get the socket and pot in and out. I became very depressed, switched it all off and got very morose for the night.
After work this evening I started from scratch. Removed the battery, reloaded the factory presets and tested. All absolutely fine. Started programming random patches in my usual locations and it was fine; sounded good and behaved well. Reloaded my saved presets and it all went to pieces again. I can only assume that my midi file was corrupted. MJMP has warned against the cheap midi interfaces and perhaps I am now learning the hard way myself.
I am, however, quite surprised that the corrupted patches would have caused all that flickering and strange behaviour.
MJMP, what do you make of this?
Anyway, thats enough typing. Now I have to get to work programming my MP1 from scratch...again!!!
This time I'll back it up on paper, laminate it and stick it on the inside of my rack.