It would be helpful if we knew the model number of the camera.
Panasonic has made at least ten 7.2 megapixel cameras.
If the camera has a lens that extends when you power-on, it may have failed to park completely when power went off, due to the weak battery.
Gently press on the front of the lens barrel to attempt to seat the lens.
Then (with a good battery) turn-on the camera.
If that does not work, some people report that they slapped the camera on the sides/bottom to free up the lens.
Don't get carried away with the slapping.
You can avoid the low battery problem if you buy a card reader.
Then you don't have to connect your camera to your computer.
I need help. I was downloading photos when my camera started flashing something in red. I assumed it was a low battery warning and continued the download hoping I could finishing getting my photos in my IMAC computer. The download completed. When I wanted to use my camera again I put new batteries in. I turned it on and nothing happened. I tried other new batteries. Nothing happened. They are installed correctly. Does anyone have any ideas? I have a Panasonic Lumix 7.2 which is about 2 years old.I did look in the instruction manuel. It was of no help.