Oh yes. I also exercised the various electrical connectors and applied dielectric grease to avoid oxidation. The plenum connections seem quite compliant. They seem as if a little deflection wouldn't cause a problem. My machine's problem is that it intermittently will have trouble starting first try....

I think the "missing screw" is a red herring. The upper case in my machine has a projection that holds the card when all is assembled. which begs the question... if the design of the 50 series was good enough, why did they change that aspect of it in the 60 series? typically, companies try to *redu...

I think the "missing screw" is a red herring. The upper case in my machine has a projection that holds the card when all is assembled. That being said, the System One 50-series has proven to be a little flaky over time. My current solution is a new 460 that I bought through Craigslist for $300. An a...

To be clear, are you talking about Philips Respironics System One Remstars?

FWIW adding the screw to hold down the board did nothing to change things on my fussy 550.

I picked up a new 60-series courtesy of a Craigslist ad and the 550 will be used only for backup.

My System One 550 got increasingly flaky the last few weeks (multiple attempts needed to start it sometimes) so I bit the bullet and bought a new 60 series thru Craigslist. The new one is noticeably quieter than the '50. With the pass-over humidifier in the circuit I literally can't hear the pitch o...

The reason to use distilled water is because it won't result in residual minerals in the reservoir as the water evaporates.

I cheat with tap water when traveling but make it a point to empty and refill the chamber every night.

Bloomfield Township, Michigan
42.605916 deg N, 83.239631 deg W

1/4 mile from the Square Lake Rd freeway ramp.

Viewing the thread on my iPad the picture posted before only showed the board to the left of the card reader. when you see pics on the forum that are too wide, right click and 'view image' and then you can see the whole thing. I'd frankly never had this problem before with other forums--usually the...

Viewing the thread on my iPad the picture posted before only showed the board to the left of the card reader. I asked to see a view of the 60 series board in order to clarify what had been described. The new photos did the trick. FWIW, my 50 series has a plastic tab molded into the top cover that lo...

Thank you!

Did you say that they do have a screw in this post in the 560? In this photo, it's along the right edge just over an inch down from the upper-right corner. I will probably have to go to the hardware store to get a screw and insulating washer of the right size. The connector and wiring for the heate...

My wife and I both use CPAPs.
I found her mask leaks waking me up and have solved it by wearing earplugs. This isn't for everybody but works very well for me.
I trust that she'll wake me up if something needs attending to.

I opened up my wife's machine to proactively exercise connectors and apply dielectric grease to each and find the charring shown in this presentation. Her humidifier had continued to work but I wanted to check out the situation. I found that the only force pressing the connector contact to the tang ...

A few weeks ago I added my Oasis pass-over humidifier between my System One and my hose and it greatly reduces the conducted sound up the hose.
I recommend it.

I know what the OP means. My original machine is a 15 year old Respironics Aria LX. It's noisy but apparently has more inertia to the blower rotor because it's pretty much steady pitch. The System One 250 that I replaced it with is set for constant pressure but the audible pitch varies up and down a...