anyone have any tips for me with my old IV-A?

[scubaops]

i checked all the o-rings and replaced the batteries. anyone have any tip using this model? its been years since i have used this. thanks

 

[jcclink]

This is a Nikonos?? Complete service - replace ALL o-rings. Dynamic pressure test (move all controls several times at depth) - check for leaks. Hope you can still buy film