Postagem original de: Owen Cunneely ,
Error 70 with the 7D relates to a battery problem. I would first, take the battery out and see if it is damaged or leaking in any way. If it is not, get some Isopropyl or contact cleaner and carefully clean the battery contacts on the battery itself and the corresponding ones in the camera. If that doesn't work, it might be time to try a new battery. Is this error something that is happening occasionally, or does it happen all the time and completely prevent the camera from functioning normally?