USE A HEPA 4 FILTER!
Foam filters stop spiders and marbles. A white HEPA filter stops dust, dead. And dust, kills blower motors.
Leaving the unit plugged-into 12-volts then starting the engine can kill off C or Bi-PAP electronics. I must have spent 100-hours at the oscilloscope on this, The power brick that comes with these machines is medical grade. Machine internals themselves have little if any suppressor circuits, because they rely on the brick to do that.
Hopefully by next week I will have a pound or so of 18-volt MOVs and 16 volt TVS transient voltage suppressors. I'm getting tired of the throw-it-away-and- get-a-new-one-mentality regarding vulnerable devices with very little use on them. And no, re-read the above - this does not encompass pnichols distributor!