How to change battery in a old Mares computer ?

[fmerkel]

Doesn't appear Brass Anchor can do it and you are out of luck with this one:

[These modules are Uwatec Digital Timers with various brand name labels on them. They have 3 silver buttons that activate the timer when wet. The batteries are not changeable but a Scubapro dealer can exchange the module for about $150. Brass Anchor is not a Scubapro dealer and no longer exchanges these units.]

 

[ScoobaChef]

Give Dive Centre Manly a call. They're pretty good with battery changes.

They also have Uwatec bottom timers if the thing is truly dead.