If the magnets are getting gunged up sometimes they don't start
(face plate off - toothbrush) and failing when you roll in is
normally battery bounce (go slightly sideways or put tape round
the batteries).
On at least one occasion I hooked a handset on something and
flipped the switch neatly to off.

nigelH

Although the 2 other replies here are posted by Inspiration owners,
you would get a lot more response if you actually joined and posted the
Inspiration list - or even checked the archives - theres a lot of stuff
in them about this, and well over 1000 other owners to ask questions to
(and listen to)

You haven't said which type of handsets you have - backlit or
non-backlit? I'm assuming non-backlit - and why are you turning them
off underwater? The only reason is to force a battery switch - if this
is whats happening, it's likely the switch jamming which it has been
known to do when under pressure - it just needs a bit of cleaning,
take the rubber boots off and clean the gunge out.

If it's backlit handsets, then as Nigel said, check the magnets.

If you have gunge in the battery compartment, then don't use something
abrasive as Pete suggests, as you'll rub away the gold-plating on the
contacts.

If they are failing underwater then it's most likely to be because the
battery has run flat.

If they fail when you jump in, you suffer from battery bounce. Turning
them on again on the surface shouldn't be any different from turning them
on on the boat. You'll only notice this if you have back-lit handsets
though, as the older ones would power on automatically rather than
needing a switch to be pushed.

Gordon

My unit is almost 7 years old and around 3 years ago I had the handsets
upgraded to the backlit version. Until recently I had suffered no problems
whatsoever. On a recent trip I experienced two problems:

1. I surfaced from a dive to discover that the Slave was blank despite the
power switch being in the 'on' position. Now it is possible for this to
happen by sliding the centre and right-hand switches up simultaneously but I
don't believe this could have happened. Never really got to the bottom of it
for reasons that will become clear in (2.) below.

2. The backlight on one of my handsets was so dim as to be useless so I sent
the electronics back to have the problem investigated. To cure this problem
I had to have both electronic modules replaced at a cost of around ?400. APD
stated that the failure of the backlight can only happen as a result of very
rough handling of the handset. Well, that is a meaningless statement. If
very rough handling can cause backlight failure then if there is a weak link
in the electronics mild handling could result in its failure. I've always
been very careful to protect my handsets.

Regards

AC