M-series APAP w/ A-Flex opened with pictures

[Craig-Tx]

OK, so I opened my Respironics M-series APAP with A-Flex. Primarily because I wanted to do something to dim the BRIGHT BLUE LEDs they use to illuminate the buttons. Don't they realize some people actually sleep with these machines?

I took pictures along the way so other geeks like myself can see what they are like inside without having to open it up and risk damage.

CAUTION! Opening your CPAP is risky. You will void the warranty. You CAN damage things. You can hurt yourself (I'm not sure how, but a talented idiot can hurt themselves on just about anything.) You can probably do a bunch of other bad things. Perhaps even cause a global thermonuclear war.

OK... Disclaimer out of the way.

You will need a T8 and a T15 screwdriver. Notice that a T15 screwdriver bit will likely not reach deep enough in the recessed screw holes.

Here are the pics

Remove the smart card module:
You can actually leave this in, I realized afterwards, that it really doesn't help to remove it. But if you want, the release is on the bottom just left of the units label. Just push on the tab and pull the card reader out.

Full Size Picture

Use a T8 screwdriver to remove the filter housing in the above picture.

Use a T15 screwdriver to remove the three screws. (1 under the filter housing, 2 in the recessed holes.)

Full Size Picture

At this point it's open.

Gently pull the top off of the bottom.

Full Size Picture

You will find a number of connections that connect the top to the bottom. GENTLY disconnect each connection.

Full Size Picture

Now that they are separate, here is the blower circuit:

Full Size Picture

Here is the control circuit, still mounted in the top half:

Full Size Picture


Full Size Picture

That ribbon cable connects the display to the control circuit. BE CAREFUL with that. Rather than risk it, I decided to just flip the circuit over without disconnecting it. There is a decent amount of slack to allow for this. If you want to disconnect it, the grey bar opposite the ribbon cable flips up releasing the ribbon.
To release the circuit, there is a small plastic tab on each side about 2/3 of the way down from the ribbon cable.

Full Size Picture

Here is a close-up of the buttons. SW3 and 4 go to the Flex button, SW7 and 8 go to the power button, and SW11 and 12 go to the ramp button. There are button pads for non-existent buttons. I wonder what they had those planned for.

Full Size Picture

There is a surface mount LED for each button which you can see in the holes between the pads.
Here is the other side showing the surface mount LEDs. They are right in the middle of the picture. Three white rectangles with a blue spot on each, in line with two other holes between.

Full Size Picture

What I did to dim the LEDs was to pack the LED holes for the RAMP and FLEX button with some liquid electrical tape. For the power button, I dabbed some more liquid electrical tape into the hole, then pricked it with a needle. This allowed a small hole to form while it was drying allowing a small amount of light to come through, so I can still see the power button in the dark. But now it doesn't illuminate my ceiling.

The good thing about this is that it is reversible. All I have to do is pop the unit open again and pull the liquid electrical tape out. Another (more daring) option would be to replace a few of the surface mount resistors with larger values. But I didn't want to risk that.

Hope this helps someone. At least it will satisfy some peoples curiosity.

-craig

[dsm]

Craig,

Great work - very good pics (obviously a digital camera )
I have been curious for quite a while

Cheers

DSM

[rested gal]

Wonderfully clear pictures, Craig! And what a clear description of what you did, every careful step of the way. Thanks for posting those excellent photos.

[Goofproof]

Good Job! Look awfully low mileage (Clean) on the inside. BTW, when you took the card reader out, did the missing data fall out? Jim

[feeling_better]

Craig, Thank you very much for the photos and the description. Excellent! [I was the one who started the other thread asking if anybody had opened it.]. You opened it just for us!! Yes, you wanted to dim that light, but you can easily do that from outside with tapes

Now I can add my remote power switch, with much reduced risk of taking it apart!! To bring the wires out, I would have to drill a hole somewhere, going to be a problem with warranty:) Usually if I do some changes, it is reversible. Drilling a hole is a bit irreversible

[rested gal]

BTW, when you took the card reader out, did the missing data fall out? Jim

[Craig-Tx]

Good Job! Look awfully low mileage (Clean) on the inside. BTW, when you took the card reader out, did the missing data fall out? Jim

Yeah.. it's VERY low mileage. I've had it for less than a week. But, I did the same dimming mod on my M-Series PRO (non-auto) the second day of ownership.
-craig

[Craig-Tx]

BTW, when you took the card reader out, did the missing data fall out? Jim

Yeah, I had 1's and 0's just dump all over my desk. I tried to put them back in, but the order got lost, so I just trashed 'em.

-craig

[Snoredog]

those damn LED's are bright little suckers, mine still give off a faint blue glow even with black tape over all 3, I just cut tiny little squares and stuffed them down the holes to cover the LED. Would have been a whole lot easier if they allowed you to simply turn them off in Setup like they had on every other machine they built in the past.

I think mine was about 3 or 4 hours old when I did that to it (I had a Cflex model before the Aflex).

[THier]

Great write up,,, I personally don't need it,,, as strange as it seems the blue light special doesn't bother me or my wife. BUT cool tear down.


OH

Shouldn't you all be asleep using your xPAPs?

Tom

[kest874]

I wonder if replacing them with red LEDs would be a good solution. Red doesn't bother most people at night like the blue does!

[feeling_better]

You will need a T8 and a T15 screwdriver. Notice that a T15 screwdriver bit will likely not reach deep enough in the recessed screw holes.

Hmm... That T8 is a really small one, not in my collection Will have to go out to buy one today.

[ractar28]

You're a geek! I only took my OLD one apart, not the new one .

I do love "press here" on the circuit board. That's the stuff tech jokes are made of.

[feeling_better]

Here is a close-up of the buttons. SW3 and 4 go to the Flex button, SW7 and 8 go to the power button, and SW11 and 12 go to the ramp button. There are button pads for non-existent buttons. I wonder what they had those planned for.

Note that there are solder-pads/holes for leds under the two unused button pads. Those who have used other Respironics machines may guess better as to what they could have been for. Here is my speculation: One was for a blue light dimming, but the circuitry had bugs, so they went ahead with a larger light button dome instead of fixing/redoing the pc board I had always thought those buttons were rather large. There is one problem with my speculation: does the light dimmer need another light?

[Guest]

My guess - at least one was for the humidifier to pre-heat? Like on the tank. Maybe both were.

I like the fact that I can see the buttons when I wake up. But then I sleep with me eyes closed too.