Does your 420E suck in air through the phone (data) jack? :o

Question for the Kleenex testers. Are you sure you're not getting a directionally-dispersed flow from the air intake itself? I assume you created some kind of vertical barrier between the intake port and the RJ11 jack just to be on the safe side.

Also, Ozij, I wonder if your 420e has a loose internal seal or gasket somewhere along the intake duct.

-SWS wrote:Question for the Kleenex testers. Are you sure you're not getting a directionally-dispersed flow from the air intake itself? I assume you created some kind of vertical barrier between the intake port and the RJ11 jack just to be on the safe side.

Also, Ozij, I wonder if your 420e has a loose internal seal or gasket somewhere along the intake duct.

That's what I've been wondering......while watching this thread progress.....

Den

100% sure about it being the jack - and I just placed a vertical seal to be doubly sure. You can realy hear the air woosh in near the jack when you place your finger there..

Could be something loose - and much as I'ld love taking it apart - I doubt I can.

I can just imagine the look on the face of the DME equivalent when I come in with the tissue test... it's not under warranty in any case... sigh.


O.

ozij wrote:I can get that Kleenex waving out on exhale even with the plug in the socket - but it won't wave in as much.

Now that I think about it your internal leak doesn't have to be along the intake duct. That RJ11 jack just may be open to the entire internal cavity, by design.

If so, then the exhaust port where your CPAP hose fits onto the machine is a great candidate for a leak as well. You might inspect that gray fitting or cuff with a very bright light. Look for stress-type cracks complements of a traveling CPAP hose.

If you get lucky and find a crack there, you just might be able to carefully seal that breech with silicone or a non-toxic epoxy. If the air breech is right where the large gray cylindrical fitting enters the housing (same gray color), then snugly seating your CPAP hose's rubber cuff against that circular entry point may help as well. In that latter scenario the rubber cuff simply blocks off the air breech as if it were a proper gasket (but only if that's where the air breech is).

Good luck!

Or you could use duct tape and partially block the phone jack at 4 calibrated markings so that you have 4 exhalation relief settings ... and have a superior machine to the Respironics and ResMeds

it has to be a leak in the air duct from the blower to the intake where the filter is.

That RJ-11 jack is simply soldered to the main PCB board, that machine is pretty compact inside.

I would also check the filter again, if you have the white fine filter in place it is probably clogged, would seem the only way it would start sucking from the RJ-11 jack.

you might also contact Puritan Bennett about it, but if you call Pleasanton I doubt very much they will help you (contact your dealer and have them call them about it).

Knowing PB, they will probably replace the machine even if it is out of warranty.

DreamStalker wrote:Or you could use duct tape and partially block the phone jack at 4 calibrated markings so that you have 4 exhalation relief settings ... and have a superior machine to the Respironics and ResMeds

This sounds technically feasible to me as well!

And just a reminder for anyone besides myself who wisely opts for DreamStalker's duct-tape calibrated comfort relief feature: first carefully check inside the phone jack for important tiny consumer messages!

Snoredog wrote:it has to be a leak in the air duct from the blower to the intake where the filter is.

That RJ-11 jack is simply soldered to the main PCB board, that machine is pretty compact inside.

I would also check the filter again, if you have the white fine filter in place it is probably clogged, would seem the only way it would start sucking from the RJ-11 jack.

The board-mounted RJ11 jacks we used years ago were open to top-side ambient air despite soldering. I could be wrong, but I don't think current manufacturing methods have financial incentive to make the top-side of standard PCB-mounted RJ11 jacks airtight.

If there's any low-impedance air path in the 420e housing's internal cavity, from front to back, then an exhaust-side breech doesn't seem out of the question to me. Air pressure has a great way of finding admittances through any channel(s) available.

-SWS wrote:

Snoredog wrote:it has to be a leak in the air duct from the blower to the intake where the filter is.

That RJ-11 jack is simply soldered to the main PCB board, that machine is pretty compact inside.

I would also check the filter again, if you have the white fine filter in place it is probably clogged, would seem the only way it would start sucking from the RJ-11 jack.

The board-mounted RJ11 jacks we used years ago were open to top-side ambient air despite soldering. I could be wrong, but I don't think current manufacturing methods have financial incentive to make the top-side of standard PCB-mounted RJ11 jacks airtight.

If there's any low-impedance air path in the 420e housing's internal cavity, from front to back, then an exhaust-side breech doesn't seem out of the question to me. Air pressure has a great way of finding admittances through any channel(s) available.

gasp wrote:I love how your mind works : ) I almost wish I had a 420 just to experiment!: )))

LOL!! Well, you saw by my edits that my mind wasn't working very well when I described it the first time! Did I ever say I was veryyyyyy math challenged? Even plain old addition and subtraction!! Too bad they didn't have "cpap" back when I was trying to understand math in high school.

Snoredog wrote: if there was an exhaust side breech it would be blowing out that jack not sucking

Ozij wrote:I can get that Kleenex waving out on exhale even with the plug in the socket - but it won't wave in as much.

That's why I originally quoted Ozij's observations exactly eight posts up when I first suggested exhaust-side leak as a possibility.

Snoredog wrote:if it was an exhaust side breech it would show up like a large leak on the reports and the machine would probably go nutso and respond as it would with any large leak in the circuit.

Gotta love hyperboles. But she's not talking about flying the national flag in a stiff wind. She's probably describing a low, fixed rate leak that the 420e would algorithmically factor in---exactly as it would factor an entire range of completely unknown yet mask-related fixed-rate leaks.

A large "nutso" fixed-rate leak would show up on the reports as excessive. Absolutely. But a small tissue-paper moving fixed-rate leak would look like nothing more than a new brand/model of mask for the 420e to algorithmically accommodate.

Despite the tissue-paper direction Ozij describes, the leak can still be somewhere on that intake-side as well. Airtight sound-deadening material so far sounds to me like the very best argument precluding any possibility of an exhaust-side leak. However, that sound deadening material sure needs be tightly packed everywhere, such that it allows for absolutely no front-to-back admittances.

If this is a big deal, post a request and I will take one apart in the morning an give a detailed report.

This machine is designed to be cooled by air flows being generated by the fan. These pass through a little hole and then flow out of the cpap housing, taking heat with them. I have never paid much attention to how much air is moving through the machine and out the RJ-11 jack. You guys ask the hardest cpap questions in the world!

I suggest that you do not modify the machine until the cooling system is understood. The machine will overheat if the heat can't get out.

DME Daddy wrote: This machine is designed to be cooled by air flows being generated by the fan. These pass through a little hole and then flow out of the cpap housing, taking heat with them.

Thanks, DME Daddy. I think there's more entertainment and idle amusement going on in this thread than anything else.

But a small amount of intentional airflow across the circuitry for heat transfer sounds right on the money. And an open RJ11 jack would be a likely exit path for even a small amount of diverted air.

I don't think there's a need to disassemble a PB420e just to prove that. But I for one would love to know just how many consumer notices are squirreled away inside that tiny machine...

Seriously, your explanation sounds perfect. I bet it will suffice for Ozij too. Thanks much!

Snoredog is right - the filters make a difference.

I still had one old - original - PB pollen filter. When only that filter was installed there was no air pulled into the jack; even when I put the machine on a fixed pressure of 20.

When either cpap.com's fine filter was installed, or cpap.com's external filter, the machine was pulling air in through the jack.

Now, the original (OEM) PB filters look much more porous than those supplied by cpap.com.

When I ran out of fine particle filters a couple of months ago, I bought a pack locally - they are much thinner than the ones supplied by cpap.com - I don't know if the thin ones were original or not.

PB's original part number for the pollen filter is: M-413950-02
PB's original part number for the fine particle filter is: M-413950-04

Those are not the numbers on my packages of filters from cpap.com

I am concerned about the unfiltered air entering the machine - especially so since there's what looks like a layer of very fine blackish dirt or dust on the inside of the LCD cover.

I don't have the equipment necessary to open those screws - they're not regular screws.
DME daddy, if you could take apart a machine and show us the way the air flows it, I would be very grateful.
O.