Wow, I can't believe no one has brought up the HV section. Slow down - check the voltages out of the DMD controller, I'm betting your 62v line has gone open.
DMD's do NOT outgas like you described, they start in a corner and take forever to get really bad. I had one I left in a game once for 3 years until I sold it, and I don't recall the tip that started outgassing even spreading in that time.