[Equipment] SmartStart not starting and "Tube blocked" error

[fasantana]

Hi,

I've been using this Resmed AS10 Autoset machine for 4 years 4 months now, no problems at all, quite good performance since day #1...  Until 2 weeks ago...
Just for the record, it hasn't had any changes in mask type/model (always Mirage FX, nasal cushion) and hose type (ClimateLine), just several normal replacements.  No major changes in the Clinician parameters, and SmartStart was always set to ON from the beginning.


Now, the SmartStart function stopped working at all.  I have to start the therapy by pressing the Start button, no problem with that, and also press the same button to stop it in the morning.  (Btw, no changes in parameters, in the settings menu, SmartStart is set to ON.)

But when starting the therapy for the first time every night, after around 1.5 minutes, the air flow stops completely, and there's a error message of "Tube blocked".  This is not real, since there's no blockage/rainout at all, and if I click on the Dial button to clear the error message, and press Start again, it re-starts and continues working correctly the rest of the night, no further interruptions.  Even if I pause the therapy momentarily during the night (i.e. bathroom visit), I still get no "Tube blocked" errors for the rest of the night, but still have to press the Start button to start/stop the therapy.

Any clue?  Any similar behavior?  I read somewhere, that the average lifetime of these machines is 5 years, so could it be starting to fail (i.e. sensor malfunction) and approaching to EOL?


Thanks in advance!

[OpalRose]

Try rebooting your device.  Pull cord from power source, wait a few minutes and plug back in.

While the unit is unplugged, disconnect the hose and double check for blockages, water, or possible kinks.

Hope that helps, but you may want to give serious consideration that the machine is starting to fail, and think about a replacement.

[ApneaQuestions]

I'm just guessing.
I tried to imagine what the symptoms might look like if a flow detector was starting to fail or act strangely.

I suppose that a bad flow detector could explain why smart-start isn't triggering if it is failing to detect your initial breathing attempts.
I also suppose that a "hose blocked" error could be caused by a bad flow detector that thinks the flow has suddenly stopped.

Is there anything strange showing up in OSCAR charts throughout the night after it gets past the initial blocked hose message?
Also, once the machine is running, does the smart-stop work when you pull off the mask (even though the smart start is not working)?

The reason I am asking is because I'm wondering if a flow detector might be becoming erratic and therefore might be causing the machine to act strangely.

[Sleeprider]

What are the machine hours/ years? I think it might be time to start sourcing a replacement. If you have a good relationship with a supplier or DME, I would talk to them about this and ask what it is going to take to obtain repair or replacement.

[3rdMarDiv]

You can also look up Supplier #27 in the Supplier List and run the conditions by them. I have been talking to them about a ResMed VAuto and I was impressed. Shipping it out to them today.

[fasantana]

       



Hi!

After several months of erratic behaviour, I just found the problem!  And have to admit that you were right, at least in part...  I'm coming back to this post to publish my experience, just if helps someone else.

First, a quick summary of the past months:
1. I'm living in Poland now. Just when I found a sleep clinic (and CPAP provider) that could give attention in English. the COVID pandemic started...
2. I decided to keep away of any health premises, unless it was a real emergency. And this was not: after a couple of minutes of erratic behaviour, I was able to sleep all night.

By the way: the CPAP was creating a register every day in the SD card, but with no data, so the charts in OSCAR were just empty, from the begining of December 2019.

But 2 weeks ago, I noticed a loose contact in the DC jack... It lost power randomly in the middle of the night, and I had to play with the DC plug until I got the machine turned on.  After extensive troubleshooting, my next step was to open the machine to verify if I could repair it, or even change the DC jack. (I'm and EE, I don't do this kind of work on a daily basis, but I have tools and soldering skills...   ).

I followed a Youtube video to see how to do it.  I found a couple of metallic parts in the jack (facing inside the machine) out of place, so I put them back in the normal position.  Loose contact problem solved!

But I continued, just for curiosity, to tear apart the pump assembly for cleaning.  And it was really dusty!  So I cleaned thoroughly, and also noticed that there is two small ducts connected to a shiny metal box in the main electronics board.  My assumption is that the shiny metallic box contains the flow sensor (or sensors?), so I cleaned profusely both, the ducts in the assembly and the sensors with compressed air.

And voilà!  Problem solved!  The smart-start functions works flawlessly now, the "tube blocked message" and reset issue stopped, and also the data registers in the SD card came back.

CONCLUSIONS:

1. These sensors need to be clean. I don't know how did the dust accumulated inside the pump and these small ducts, maybe the filters are just not perfect, and this is noticeable after several years of use.  I've seen this erratic "tube blocked" warnings in other posts, where there's obviously nothing wrong with the tube, mask, air outlets or humidifers.  This is just another point of failure that could be reviewed as a troubleshooting.

2. About the DC jack. The loose contact I detected (and solved), was caused just by mechanical wear of the connection, I mean, after hundreds of connect/disconnect actions. This jack looks like those in many laptops, not cheap and not easy to replace, since they have many soldering points.  I wonder which are the best practices for this situation: in my case, I always keep the CPAP inside the original case during the day, so I plug it in every night and pug it out every morning.  Evidently, after 4+ years of use, the jack got damaged. Any idea?

[upsman]

 I wonder which are the best practices for this situation: in my case, I always keep the CPAP inside the original case during the day, so I plug it in every night and pug it out every morning.  Evidently, after 4+ years of use, the jack got damaged. Any idea?

What is your reasoning for doing this? 

[mesenteria]

Yeah, it’s my first question as well. I leave my machine inside an open night-table drawer, always powered. My only “unplugging” is to remove, rinse, refill, and to reinstall the water vessel, and then only every four days when I’m low.

I’m no engineer or expert, but I don’t put much stock in the standard filters. Mine last literally months without discolouration that leads me to switch them out. I’m quite convinced that the impeller is about as dusty as that found in a six month old laptop or desktop cooling impeller now that I’m three years in.

[upsman]

Yeah, it’s my first question as well. I leave my machine inside an open night-table drawer, always powered.

Yeah, me too. I see no reason to ever unplug my machine. 

The only time I have was to travel with it and an occasional reset. The less it’s handled the less opportunity for damage. 

[Sleeprider]

If you really feel the need to disconnect the machine on a daily basis, put it on a switched surge protector. The only time you need to unplug the machine is for travel or maintenance.