16 volt supplies are hard to find. I did find one by Acopian for $270.
I can get the orginal with some wait for $150. I looked at the supply
and its varying voltage constantly resetting. Nothing obvious I
can find.



Did you check the ESR of all the electrolytic capacitors? That's where I
start when diagnosing switchmode power supplies.

Probably doesn't have to be 16V exactly, 14-20V or so would probably be just
fine, but I don't think the original supply should be hard to fix. If you
don't know how, take it to a tech who does.