Apollo AV1: Faulty reed switch/trigger?

Hi,

I have a new AV1, (Less than 6 months old) and have a few mates with units
about 4 years old. None of us have had issues with the reed switch.

We are aware of this mod:
http://www.cisatlantic.com/trimix/Ap...Triggermod.htm

But I have another mate, who has bought a much older unit. (I would guess at
least 8 years old)

This came with 10 spare reedswitches!

On our first dive, the switch failed, and the unit would not stop.
Thankfully it happened on the surface, so he had it disconnected quickly.

He then swapped the switch and all was OK on the second dive.

My question. Does anyone know if early Apollo AV1's had issues with the
reedswich assembly? Was this a known problem? Any ideas why one scooter
would be more susceptible to failure than another??

I don't really want to open mine up, so I can't say if they are different or
not. The outside looks identical.

I think Pete Young has an AV1? Maybe you have some experience with this?

My buddy is deciding if he wants to return the unit to the second hand
seller as being "Faulty" or not. The seller said that there were often
issues with the reed switch and that was why he had so many spares...

Also is it normal that the switch will fail "On" I had been using the thing
on a mix dive, and if that had happend, I would need to have bagged it off,
and hope for the best. Not really what you want with £1000 worth of kit.

I had expected it would fail "Off" (I'm not talking about it sticking at
depth, but the actual switch breaking like his did on the surface)

mattD.