Hi 5440ks,
I understand you're having an issue with your Officejet 6500. I am sorry to hear this has been happening but will do my best to help you.
Before I make any other suggestions, have you followed the steps in ShlomiL's post just above? Those steps should help resolve your issue.
Also it's best to make sure that your printer is plugged directly to a wall outlet to ensure your printer is getting enough power to function properly.
Hope this helps, have a great day!