[Equipment] Need Help with Resmed H5i Humidifier

[DannyV]

Hi Folks,

I accidentally damaged the hidden printed circuit board inside my Resmed S9 Humidifier's (H5i) Base, 
and I'm hoping someone can help me out please.

I'm looking to either:

1. Get someone to simply tell me what the part number is if it’s written on it.  OR 
   
2. Get a really close up Photo of the part of the PCB that I damaged (so I can see the part that I drilled off). OR
   
3. Get a copy of the Schematic Diagram (circuit) of the H5i PCB, OR
   
4. Buy a H5i PCB only, OR
   
5. Buy a Second hand H5i (base part only with included PCB).  
   

Any of the above help would be very much appreciated indeed!

Background: It's my own silly fault, I modified my unit so that it automatically refilled itself with water - that worked great - then I 'neatened' it up by hiding 2 water level sensor wires. 
I drilled a couple of 1mm holes for them ….. straight through the PCB.  
 Blast. I thought I would have been well clear.

However I am a pensioner with plenty of time & an ex repair tech, so given an idea of the missing component, I can fix it.   

Here's a close up of the damage (the hole is only 1mm big)
   

Not Quite so close:
   

A view of where the PCB is (in the Right Hand Side):
   

[Sleeprider]

A complete H5i humidifier with warranty can be obtained for $90 with free shipping from Supplier #2

That was a clever piece of engineering other than penetrating the PCB. If you buy the replacement, you will have lots of spare parts, and the price isn't too bad, all considered.

[foxfire]

Q7, the 8 pin device on the right is a MOSFET transistor, Siliconix p/n SI4447DY. Q1 and Q11 to the left of the hole are NPN and PNP transistors used to drive the gate of Q7. Resistor R58, which is 47 ohms is the turn off resistor, the missing resistor will be the turn on resistor.

There is another SI4447DY, Q8, just below Q7, there should be another pair of transistors and resistors that drive its gate nearby. If you follow the PCB trace from pin4 of Q8 you should be able to find them. When yo find them the turn off resistor is likely to be 47 ohms like for Q7. The other resistor will be the turn on resistor which will be the same part you will want to use to repair the place where you drilled the hole.

[DannyV]

Thank you Foxfire, That is most informative. 
I'll pop a 47 ohm resistor in there.
Thanks very much.  

[ShaunBlake]

Please don't forget us! A lot of people are interested in how your repair works; it would be great if you would update the thread with the outcome.

[JesseLee]

I'm interested too. Did something similar in a project for a keurig coffee machine. Never thought of an application for cpap refilling. Id like to know more about the entire setup. What kind of water is dispensed? Pumps from large reservoir?

[Sleep2Snore]

It is a surface mount 47ohm resistor that has been knocked off by the looks of it.
I don't know the rating of it, but if you are stuck stick in a normal one if you have the room, but make sure it has a high enough rating. 47R0 is 47 with no multiplier, so 47 ohm. Put in a metal film if you can't get a surface mount.

[DannyV]

Hi Folks, an update...
No I'm used to using SM devices and carry a swag of stuff for my hobbies, so I fixed it without any problems, (along with the divided track on the reverse side by the top hole).

What's more - it now works.   


So I'll try it out tonight and as soon as I find the pump and level sensor I'll replace those bits and post some photos.
Basically all it did was, when the float inside the chamber got low enough, it started to slowly pump filtered water from a plastic bottle into the chamber (via a plastic tube sealed through the top cover) until the float hit the top mark - and then it stopped. (I've temporarily sealed the holes up tonight).
When the external bottle got low enough, I just refilled it - it's easier to get at, because the CPAP unit is hidden in behind a little TV (security) monitor.

[JesseLee]

Thanks for the details!

[ShaunBlake]

Oh my, DannyV you're my hero; sure am glad you've joined the family fun forum!

Hey, this would make a great YouBoob video! Whaddaya tink maite?