My camera started to malfunction a few months ago. The basic problem was that the hooks that latch the battery door shut had broken off. This meant that the connections to the batteries were bad and that the camera shut itself down while trying to do anything that needs a bit of current. Like taking pictures.
My solution was to remodel the battery cavity to accept a nine-volt battery and to solder a battery clip into the system. This seems to work, even though the original set of batteries was six volts. I assume it has a regulator, while CMOS is quite forgiving about it’s “on” voltage, I can’t imagine something this complex being universally good at three volts over. I’m still not sure it is fixed, I haven’t tried running it for any length of time, but it has taken two pictures happily.
I hope this works out. I can afford to replace it, but the money is better off being spent elsewhere.