I have an old, formerly reliable 505DS that I stumped by. It turns on and runs for 10 seconds and then shuts off with a "short cycle" error (the two bottom diagnostic LEDs ON). I have taken apart the valve assembly to check for debris, etc. Along the way, I tried running it with the purge solenoid disconnected and it remains running and the oxygen sensor does NOT show "low oxygen"! Reconnect the purge solenoid and seconds later, it shuts down. If anyone has seen anything like this in any of the 500 series concentrators, please let me know! Thanks!
Equipment: DeVilbiss - 5 Liter Oxygen Concentrator
