Imac monitor

Last week I was having trouble keeping my wireless mouse connected. I decided to restart the computer, thinking this may help, and then the monitor picture would not come on. Next I shut down the computer and unplugged it. When I turned it back on the screen did come on. I put the computer to sleep after that. Since then I am unable to get any picture. Anyone have any ideas?

How old is that mac and has it had any knocks recently

December 2006, and never moved.

Someone told me it could be a RAM issue. Does that make sense?