JUMP
Registered
It is true that manufacturers will stop servicing older models, but you can never know after how many years. It's probably a function of how many models they crank out each year and how different they are.I met someone on a recent trip who complained that they could not get their 10+ year old hyperaqualand serviced anymore (Citizen offered to sell them a new one). I guess that would be true for most dive computers too, but a bit disappointing, if I got the facts accurately (second hand is always risky).
There are however, plenty of private watch repair 'gurus' who service weird vtg stuff. If a quartz watch (like the hyperaqualand) has been well looked after, all it should need is a new battery and some fresh gaskets, which is easily done (you know, provided you can find a gasket kit).
Dive computers are pretty much the same. If you have one you really like, it doesn't hurt to pick up a few spare parts for it while you can so you or someone else can service it instead of the manufacturer.