[Equipment] ResMed S9 changes mode

[justMongo]

I'm designing a hanger to hold my power brick just behind my night stand. It will include a 120mm slow speed, low noise fan to keep it cool.

[geoffleach]

Power is being supplied by a Trace 4124 inverter. It has been supplying reliable sine-wave 120 VAC power for 20-odd years, so no reason to suspect it. The power supply and air intake are both free of covers and/or obstructions. that said, I think it best to assume that there was a momentary glitch in the power, Mea Culpa.

Thanks to all who replied. It's nice to have friends.

[RonWessels]

The first power brick that came with my CPAP unit was actually faulty and had an intermittent open circuit at the connector. Most of the time, it worked OK, but if the power cord was touched (eg. cleaning), it often behaved as if it wasn't plugged in. Fortunately, I was able to quickly diagnose it when connecting to a DC battery source using a different cable worked flawlessly. And the new power brick also worked flawlessly.