Resmed S9 Elite Teardown with pictures

Hi All,

I've been looking online for instructions to self-repair a Resmed S9 without luck, so tonight I tore mine apart because it was making so much noise I couldn't use it, anyway. It turns out it was the humidity sensor airflow tunnel (I think) that was causing the noise. Anyway, here are the instructions:

*** You will need a Torx 10 screwdriver for disassembly. Do not use a phillips screwdriver, you will damage the screws. It must be Torx 10. You will also need a flathead screwdriver and possibly two smaller screwdrivers as well. ***

1) Remove the power cord (duh!) and the SD card, as well as the air filter cover. Pry up the control knob and remove:



2) There is only one screw on the outer casing you need to remove before taking the S9 apart:



3) The top and bottom plastic covers are held on with plastic clips on the inside. You can use a screwdriver to gently pry each half off, moving along the edge two inches or so at a time:



There are two particularly stubborn tabs you can reach from the outside with a small flathead screwdriver to remove the top. You can see the fruits of my bad screwdriver work before I realized how to release those tabs:



4) Once the two covers are off, you need to remove the circuit board. Ground yourself! Static electricity can damage the board! There are two screws that hold the board on, and a clip for the power jack that must be unclipped in step 5. Remove the two screws first:



5) In order to lift the circuit board off the frame, you need to unclip the power jack. The clip is accessible from the outside of the housing. You'll need to use two implements (I used two small screwdrivers) to pinch the feet of the clip sideways towards each other to release it:



6) Gently lift off the circuit board since the power plug for the motor is still attached. There are a few items to note: The power cord for the motor, the CMOS battery (if your CPAP loses time while unplugged, you'll need to replace this), the two black plastic ports that line up with the two holes on the base (for the humidity sensor) and the small gap at the front of the housing that the motor wire runs through. Take note of that gap - you can't get the covers back on unless the wire is placed back in there. Remove the power cord for the motor from the circuit board.



7) You'll have to trust me on this one. Even though you can't see them, there are five Torx 10 screws that hold the motor housing to the chassis. Follow the arrows and remove the five screws:



8 ) Disassembly is mostly complete. The fan unit is housed in a rubber shell which is keyed with inserts so you can't put the blower in the wrong way. I was looking for a part number in case I had to replace the blower, but there was none to be found. The plastic case that shrouds the motor and fan assembly is glued together and can't be taken apart without breaking it. In my case, the air redirector for the humidity sensor had dirt in it (the light brown tube in the picture), which made it whistle when the unit was on. I blew that out and the fan blades with some compressed air and the noise went away after re-assembly.



Putting it back together is simply reversing the steps. The plastic clips on the outer covers are particularly stiff, so you'll need some pressure to get them back on. On the top cover there are two clips that mount on the circuit board - be gentle when pushing those back into place.

I hope someone can use this. I could not find a guide online for the S9 anywhere that included instructions for taking it apart.

Well, thank you for that. However, I'd drop mine out in the middle of the ocean before I'd attempt to do what you did.

Excellent step by step. I hope I never need to follow it, but if that becomes necessary it is comforting to know that this reference is here.

Thank you.

So why don't you replace the "humidity sensor airflow tunnel" and reassemble the Elite? BTW, there is no such thing as you say. You either have a humidity sensor or an airflow tunnel but not both as a unit. Also, how could a sensor make noise?

avi123 wrote:So why don't you replace the "humidity sensor airflow tunnel" and reassemble the Elite? BTW, there is no such thing as you say. You either have a humidity sensor or an airflow tunnel but not both as a unit. Also, how could a sensor make noise?

Geez Captain Snark, I'd replace it AND the blower assembly if I knew where to order parts. I've searched and searched online and come up empty. And that little tunnel unit just redirects air up to what I assume is either the humidity sensor or a pressure sensor, but without a schematic I'm not sure which. In either case, it had dirt in it, I cleaned it, and the machine was quieter. Looking back at it it's probably to measure the pressure.

Thanks for this interesting info. Somebody else recently had a post on taking apart a PR S1 Auto. It was nicely detailed with annotated photos in the same way you laid out your excellent document. At the end the poster briefly compared taking apart a PR vs an equivalent Resmed. I remember he also mentioned that the ResMed S9 plastic clips after reassembly can fail to securely hold the chassis tightly together... he then suggested using some shims to get the juncture tight (he didn't go into detail on the shims). Did you experience that at all?

Sir NoddinOff wrote:Thanks for this interesting info. Somebody else recently had a post on taking apart a PR S1 Auto. It was nicely detailed with annotated photos in the same way you laid out your excellent document. At the end the poster briefly compared taking apart a PR vs an equivalent Resmed. I remember he also mentioned that the ResMed S9 plastic clips after reassembly can fail to securely hold the chassis tightly together... he then suggested using some shims to get the juncture tight (he didn't go into detail on the shims). Did you experience that at all?

I didn't, but I was careful putting it back together. Since I could see all the clips after I took it apart, I worked them from the smallest (the ones that went through the circuit board like I mentioned) and then towards the outside. For the two tough ones I pointed out for the top, I had to use a flat head screwdriver to ease them into place. Snapping the covers on was definitely not a one minute procedure. If you happen to crack one of the plastic clips, then using a shim would certainly be a solution to secure the top or bottom and prevent vibration. They are only cosmetic covers.

The screws and the rubber seal are the most important and functional parts of the S9, and if you follow the instructions they are all outlined correctly. The plastic covers are only for show.

nashbridges wrote: I'd replace it AND the blower assembly if I knew where to order parts. I've searched and searched online and come up empty.

It appears to me most XPAP machines are not designed to be repairable. The manufacturers want you to shell out for a new machine every couple of years.

If the pictures are any indication of your cleaning regime... I can well believe that there was dirt on the inside. You have to wipe down the outside of the machine from time to time to keep the dust and grime from entering inside through the little cracks and crevices. Just changing the filters every two weeks is simply not enough of a cleaning regime to keep the area and machine clean. Most DMEs have a repair facility within their business or better still there is a repair company that comes here on the forum and will offer to fix our machines. I don't know the name of the company, but someone that does will chime in and give it to you... actually I think Pugsy knows who they are ... send her a pm and she may be able to dig up the name of the company.

nanwilson wrote:there is a repair company that comes here on the forum and will offer to fix our machines. I don't know the name of the company, but someone that does will chime in and give it to you... actually I think Pugsy knows who they are ...

Forum member ID for that company is Accurate
Their website link below. They do have a link to their website in their member profile.
http://www.acbio.com/

It is who I would use...my DME doesn't do any repairs...I don't think that DMEs doing anything beyond the very basics is going to happen here in the US. Maybe they do in your neck of the woods.
I would never take a machine apart...I have a long history of doing a great job disassembling something to fix it...but horrible job with reassembly. I know my limits and this is one of them.

[quote="nanwilson"You have to wipe down the outside of the machine from time to time to keep the dust and grime from entering inside through the little cracks and crevices. Just changing the filters every two weeks is simply not enough of a cleaning regime to keep the area and machine clean. [/quote]

I'm a clean freak... a well known clean freak in my family. I change the filters regularly and occasionally wipe down the area where the water chamber is, as well as the outside. That's about it tho. Taking the machine apart to clean the inside is overkill. Even if I could easily do it, I never would. Even my sleep doc/pulmonary specialist said it was a waste of time.

nashbridges wrote:

avi123 wrote:So why don't you replace the "humidity sensor airflow tunnel" and reassemble the Elite? BTW, there is no such thing as you say. You either have a humidity sensor or an airflow tunnel but not both as a unit. Also, how could a sensor make noise?

Geez Captain Snark, I'd replace it AND the blower assembly if I knew where to order parts. I've searched and searched online and come up empty. And that little tunnel unit just redirects air up to what I assume is either the humidity sensor or a pressure sensor, but without a schematic I'm not sure which. In either case, it had dirt in it, I cleaned it, and the machine was quieter. Looking back at it it's probably to measure the pressure.

it's an airflow sensor, it measures the pressure differential before and after the baffle that's in the middle of the bit you cleaned out, thus letting the machine calculate the airflow. the pressure sensor is the other little sensor near the motor connector, (you'll notice it's right near the exaust port.)

as to mr snarks comment, there's no need to replace it, as long as it's not broken. (I've torn apart a an elite, and a adapt, ... the insides of the two units are *identical*... the only difference in them is the software)

nanwilson wrote:If the pictures are any indication of your cleaning regime... I can well believe that there was dirt on the inside. You have to wipe down the outside of the machine from time to time to keep the dust and grime from entering inside through the little cracks and crevices. Just changing the filters every two weeks is simply not enough of a cleaning regime to keep the area and machine clean.

that's overly condescending, and inaccurate.

the air handling unit (that's the module in the pics that takes five screws to open) is thoroughly gasketed, with only six openings, one large one for air intake, one large one for air exit, two for airflow measuring, one for pressure monitoring, and one for the wires to the blower motor. the only places dust can enter is through the air intake, which should have a filter over it.

any dust that could creep into the machine, (what is it with people thinking dust is on a forced march into the innerds of things) won't affect it's operation, since the only bits it could get to is the circuit board.

I had a s9 elite that I'd not bothered to dust off in a couple of years, I did wash the filters every few months, but that's it. I recently dusted it off and ended up taking it apart to swap some parts with an adapt i'd bought second hand that turned out to have been used by a smoker.

guess how much dust was in my unit that I hadn't dusted in a couple years? that's right, none, not one bit. I swapped it's clean silicone bits for the stinky ones in the adapt, and gave the now fresh smelling adapt to a friend with csr that desperately needed it, and set about de stinking the icky ones.

(btw, oxyclean with get the yellowing out of the silicone, and trips through the dishwasher gets rid if the smell better than anything else I tried).

i found a resmed vpap s9 for sale but it has an odor do you think the blower blades can be cleaned. and how would you do this?

vicpete wrote:i found a resmed vpap s9 for sale but it has an odor do you think the blower blades can be cleaned. and how would you do this?

You didn't have to resurrect this thread to ask that question.
Go up to the Search line and do searches on "odor and removing" and "smell and removing" and start sorting through the posts and threads.

Numerous ways to do it, depending on what the "odor" is. Replace the filters and let it run for awhile. Preferably outside to draw in fresh air.

Taking it apart to "clean" it is foolish and unnecessary. The blower inside is a sealed unit. Trying to take that apart would be a sure way to ruin the machine.