I unsoldered the battery from the circuit board and left it off for several days. While this did reset the clock it did *not* reset the motor hours. I must say that my motor was still very quiet, and when I got it out it was not that dirty... so it's in the new box on a shelf waiting for need. My understanding is that my old S9 has the same motor... but it never complained either. Took pictures of the board, got PDF's for all chips of note... STMicro doing a good business, 32-bit and 8-bit jobbies in there. No bare EEPROM's to read/erase, more's the pity. A10 hackers PM me please, I do embedded for a living. I know about the covid/ventilator thread, I'll be checking that out soon.
I did not bother re-installing the 3G modem... anyone wants it, PM me... both my A10's are now C2C. Anyone wants to send me a 4G modem, PM me... I'm not worried about my data, and my doctor is P*ssed off that my machine is not phoning home (and has no clue about Oscar etc). When he asked me for my 'chip', I said "you mean the SD card?"... jeez. At least I got the prescription renewed... one place I use (the one with the black friday sale) told me that once they see a scrip it's good *forever*... doc was P*ssed to hear that! The mask I wanted was not in stock so I sent the new scrip to the easy breathe place... good for 8 years they said. Medical insurance is a scam in USA, anyone ever tell you that? I don't even bother, just out of pocket for all of it. Love the fact that CPAP runs on 12c/kWh juice and 1000g/$ water... a little PM every decade is no problem.
Got the motor from the smiley-faced prime company... they're all the same I understand. Cost about 130USD. Uncle Nick sells motors, you need to be a member... same for his Magic Uploader. Working on the wifi SD card thing, that's in another thread... hate it when I forget to reinstall the card, Oscar tells you (for 0.5 seconds) don't forget! Tried Sleep H Q, prefer Oscar, don't you?
I used Uncle Nick's video for disassembly/assembly... he doesn't cover some things, so you have to look for the locking tangs that hold the hose bracket and the power connector to the case. Strong flashlight and common sense helps here. I did decide to disconnect the hose heater flat cable, just pull gently and it comes out of the friction connector on the circuit card. When you re-insert it make sure the metallic side is *up*, away from the board... the contacts are (counter-intuitively) on the side away from the board. Complete disassembly makes the cleaning easier.
I got the solder-in battery from the DK company... the M company didn't have them. You have to look for the 18mm contact spacing instead of the 20mm spacing. The Panasonic part number is BR-2032/GUN, the DK partnum is P241-ND. The old battery still had 2.9V in it without load... probably good for another five years, but if you are handy with a soldering iron and you're in there anyway, why not? Also, I thought it worth a try to see if the motor hours would reset... no such luck... modern IC's have EEPROM memory that doesn't go away with power loss... that battery is only for the (not very accurate!) clock. Not even sure if the modem (none of my A10's have a modem that works) would reset the time... we're very used to electronics that just knows exactly what time it is, sadly. The time skew in Oscar would be minimal if my A10 and O2Ring would just sync up automatically.
Uncle Nick doesn't take you through the heater pad... I went ahead and removed/cleaned/reinstalled it. The active element appears to be a spiral printed circuit on the back side of the plate... there's a stainless plate in between and a silicone piece to hold them. The printing on the plate said 8R5 5%... with my cheeseball ohmmeter I measured 8.3 ohms (8.5 with .2 ohms in the leads). You can also check the ohms of the fuse that's readily apparent... should be a direct short. There's a few thermocouples on there that I could not check... just glad to feel it heat up when I reassembled the thing.
Some convenience items were
a) a brand new 12qt plastic dishpan... I don't trust my sink for breathing machine stuff! Used for the soap wash.
b) a plastic 2lb coffee 'can' of the F brand for vinegar soaking... about 6x6". Used for the vinegar soak.
c) must use a Torx T10 driver. I used a power screwdriver because I'm elitist (and I have arthritis).
Most of the screws are the same size... the four holding in the heating pad are shorter. I had to disassemble and reassemble several times... that little foam donut? You'll probably forget to put it in the motor case. The heating pad wires? They need to snake back in *before* the circuit card is installed... put the heating assembly in first. Don't put any long screws back in until you've put the thing together, there's several things held by one screw... there's one screw on top holding the pump housing, that one goes in first. If you follow Nick's video slavishly (like I didn't) in reverse you'll do OK. Nick's assembly is terse and sped up, so scroll backwards in time for your reassembly. Make sure the little fiddly silicone bits that connect the pressure sensors (there are three) are seated. Q-tip clean and blow out any passages you can reach.
My case had water/lime stains around the chamber and heat pad... so that end of the case got a good vinegar soak (you *must* remove the heater for this). Scrub all affected areas with a toothbrush and vinegar after soaking. Then wash all plastic and silicone parts in the (new!) washtub with hot water and a spritz of dish soap... rinse thoroughly and let dry. Go over parts with a Q-tip and Windex where crud still clings (the water compartment). Make sure you pay attention to the silicone seals for both ends of the water compartment... the tang holding the silicone/plastic assembly for the pressure output must be pushed in pretty hard to release it. While my tap water is not perfect, it's never given me any diseases, and I'm not fastidious about cleaning my stuff... I do buy a new chamber once a year, and I clean with a vinegar soak every couple months. If you never run it dry, and rinse it completely before refilling, the build-up is negligible (for my city water).
I did not vinegar the pump housing, no need. Only the wet end of the case got a vinegar soak. I disassembled the heating pad and soaked the silicone. I cleaned the stainless plate and ceramic heater plate with a vinegar swab, then Windex. If you half-invert the silicone motor case it goes on much easier... pay attention to the video, the wires come out to the right of the silicone double-tang... the cut in the foam piece goes there where the wires exit. There's a notch in the pump housing, don't pinch the wires!
After assembly run some air through it before you breathe it! First run should be with no hose and no filter... just blast it and see what comes out. Your machine will error out on no hose... connect the hose and chamber and try again. Next put a filter and mask and give it a rip. My old A10 is now quieter than my new one it seems.
I'm going to run the old machine for a while and see how it goes... I bought a new card-to-cloud A10 for black friday prices so I'm pleased to have two perfect A10s in new shape, one for backup. Not sure if you've ever tried to sleep without CPAP after 15 years at 10+cmH2O but it's not fun... did that once, forgot my machine, had to sleep in a hotel chair. I keep *two* generators on hand if the power goes out (I live in Greg Abbott's Texas)... might be time to check into a battery solution, I run mine on my computer UPS anyway but it'll only give an hour or so... good for brownouts.
Anyway thanks for reading this far, I couldn't find a thread with this exact info so here's my effort. There are a bunch of YT's on the motor replacement, use them. Really fond of the A10 APAP, especially since I can field-strip one in 10min with a power screwdriver now!