If you're using rechargeable batteries of the common kinds, many of them seem to have a tendency to build up an "insulation" on the battery terminals, especially during the first few recharges. The effect usually is less common once they've been through a few recharge cycles, but you may still see some corrosion that blocks the contact. Wiping the battery terminals fairly briskly on a course bit of cloth usually is sufficient to remove it, if that's the problem. The contacts inside the camera can also get "dirty," and the same sort of cleaning may be needed.

You should NOT use anything abrasive on either the batteries or the inside contacts., but making them "shiny" with a cloth may help.

Of course it is necessary to be sure that the batteries are fully charged. Some chargers indicate when charging is complete and some do not. A first charge for a new set of batteries usually takes at least 18 to 24 hours, depending on the charger.

If charging the batteries, cleaning the contacts, and perhaps trying a different set of fully charged batteries doesn't work, you most likely will need to take it to a qualified service place, or try to get an exchange if it's new enough.

John