Yesterday I had a new sleep study, and they recommended settings my old CPAP didn't have, and my current (lack of) insurance won't buy a new one. So, I decided it was time to break into the machine again and look for the problem.
The last time I did, I only checked the humidifier and found no problems with that. Not really sure why I stopped at that point, but, whatever. I opened the CPAP (2 screws on the bottom is all that's holding it closed, Torq driver t15, so, not a big deal.) Once you get those out the top pops right off, no clips or anything. The knob on the top is pretty tough to get off, but it has no glue or clips or anything holding it on, so I just slid a wide flat head under one side, pried a little, then the other side, pried a little, until it was up about 1/4 inch, then I pulled it off with my fingers.
Once I opened it up, the problem was very obvious.
Once you get the knob off the top (The casing around the sd card slot will probably fall out, so make sure you catch that!), the circuit board will be free from the top piece, attached to the base by 3 connectors, all different sizes, and only fit one way, so there will be no problem reconnecting them without any notes or markings. (top of photo, 2 pin green one, 3 pin red one, and a 4 pin white one.)
See the burnt spot on the white one. The casing around the connector for the RED wire was melted(I assume poor contact and too much current caused it to over heat and melt/burn)
(top right of photo)
It was late, and no stores were open, and I don't like to wait, so I used a tiny screwdriver, pushed in on the wire, then press down on the clip on the back of the connector (for those who don't know, there's a little rectangular cut out on the back. TOWARDS the end with the wire, it's very difficult to see in that tiny slot, but the metal is bent up to keep the connector from pulling out.) while pushing down, pull the wire back, and it should slip right out.(See the darkened pin at the top right)
Once you've got the wire out, grab some fine sand paper, (like 200+ grit, maybe even 100+) and sand the metal connector till it's silver again. Then sand the pole sticking out of the circuit board till it's silver. the contact area is on the side of the bar you CAN NOT SEE, so sand the top, and remember how much effort it took, then sand the bottom with at least that much effort. (slide your sandpaper under the bar, and over the one next to it (there's a small gap between those 2 poles) then just pull your and paper back and forth a few times. It would probably be a good idea to apply some de-oxidation paste on the pole. I can't confirm that will help, but it sure wouldn't hurt, and it seems like a logical solution since this is most probably the power pin.
(I guess this photo is not really any help)
Once you've done that, slide the connector back in the case (make sure you insert it with the little tab pointing toward the slot) push it in till the connector disappears, then try to pull it out, it should be locked in, if not, try pushing it a little further. if you can't make it lock, pull it back out, slide a razor blade between the connector and the tab, that should pry the tab up enough to keep it locked once inserted (it doesn't need to be very far from the connector. not even 1/16th of an inch!)
Once the connector is back in the case, plug it back in (again, it'll only fit one way.) then plug the other 2 connectors back in (still, they'll only fit one way and in the right places) Once those 3 connectors are plugged back in, push the sd card casing back on (the thinner side goes toward the top.) then press the circuit board onto the base of the CPAP. There are a few little tabs to ensure it's in the correct place.
Then put the top back on, push the knob back on (it's keyed, so make sure you align the notch!) flip it over, put the 2 screws back in (don't over tighten, it's just plastic. a slight increase in tightness is all you should turn it to)
Thats it! Your humidifier is repaired. And it cost nothing! (well, assuming you have a torq screw driver, and some sand paper, (and de-oxidizer if you so choose. I didn't, which means I'll probably have to do this again, and then possible even have to replace the connector.... But, if that happens, I'll let ya know )
