Scubapro MK25, R390 second stage problem

[roger]

Hi, not sure if this is the right place for this, but I'm having a problem with my Scubapro reg, basically the second stage primary, suddenly is not 'breathing', if I purge then only a slight hiss of air comes through the reg, the secondary (or alternate) is functioning perfectly.
I have serviced my old MKII reg loads of times and am a certified Mares after sales service technician, as part of my job I service all the dive centres regulators, Aqau lung & Sea Quest and have never come across this problem before, I don't know if this is a common problem or if anyone has come across it before. I don't have the correct tools to pull the first stage apart and have investigated as far as the tools I have for the second stage, just thought I'd ask here before going any further, being on an island means I can't get first hand advice from a scubapro registered service centre, unless someone knows any where I can get this advice.
Happy diving and thanks in advance for any advice etc
R

[awap]

Two possibilities off the top of my head. Something clogging the hose or a damaged lever. Start by removing the cover on the R390 and inspect the lever. Just remove the plastic pin with a knife and unscrew the cover. Try operating the lever directly. If that does not uncover the problem, use a pair of pliers and a rag (to protect the scubapro knurled nut) and remove the R390 and take a look for obstruction. Then see how much air blows thru the hose.

[hooligan]

I know I might get flammed for this, BUT.... Over on scubaboard.com there is a guy named DA Aquamaster. I think he knows more about scubapro regs than scubapro themselves do . Anyway, you might want to ask him.

[ScubaToys Larry]

Originally Posted by hooligan

I know I might get flammed for this, BUT....

You have 330 posts on this board... Have you ever seen anyone get flamed for trying to help another diver?? I have no problem with your post - nor should anyone else. If anyone ever sees flames on this forum - let me know and I will extinguish them.

[mitsuguy]

Originally Posted by awap

Two possibilities off the top of my head. Something clogging the hose or a damaged lever. Start by removing the cover on the R390 and inspect the lever. Just remove the plastic pin with a knife and unscrew the cover. Try operating the lever directly. If that does not uncover the problem, use a pair of pliers and a rag (to protect the scubapro knurled nut) and remove the R390 and take a look for obstruction. Then see how much air blows thru the hose.

yup... I agree... I have the tool to take the R390's apart (its the same as the TUSA S-60 second stage), but you can get it done with any spanner, or even a set of pliers possibly...

Once in there, you might find something stopping the demand lever from moving, or it might be bent, or out of place... By removing the cover, it should be pretty evident, hopefully...

To ensure it's not the first stage, and knowing the octo works, just swap hoses and ports - eliminate the easy stuff first... You might also test IP and make sure it's between 125 and 145 psi...

[hooligan]

Originally Posted by ScubaToys Larry

You have 330 posts on this board... Have you ever seen anyone get flamed for trying to help another diver?? I have no problem with your post - nor should anyone else. If anyone ever sees flames on this forum - let me know and I will extinguish them.

I wasn't actually concerned about it, just said it tongue in cheek for my reference to scubaboard. I've never been flamed on ScubaToys, that's why this board is so great!

[roger]

Thanks for your help, I'll take what you've said and give it a go.
R