Why won't my 5D Mk II turn on?
I flip the power switch to the on position but nothing happens. How can I turn my camera on?
The Canon EOS 5D Mark II is a 21.1-megapixel full-frame CMOS digital single-lens reflex (DSLR) camera with video recording capabilities.
With issues like this, you should really add a bit more info if you can.
Is it a genuine or aftermarket battery. Are you using a battery grip. Was the camera acting up before it stopped turning on. Was the charge status of the battery indicating it was bad in the battery info menu? Was the camera dropped. Was the camera used in an unsuitable environment.
The more info we get the easier it will be to help you out.
A couple of non obvious reasons why it might not turn on...
There is a switch on the bottom of the camera where the battery door is. The camera will not turn on if this is not depressed. The door depresses this when it is shut, so if the door isn't shut quite right, then it wont turn on.
Same goes for the CF card door. If it is not closed and locked into place correctly, the camera will not turn on.
I have same problem with my camera 5D ii, problem started while i was on set, shooting pre-wedding. Problem started slowly, camera stopped working and i tried to remove all batteries including clock battery and CF Card and it turn back on again. I did it several time and it working again but now the problem get worse, IT STOP WORKING COMPLETE (can't turn on again).
Sorry for bad English it not my native language.
Usually, there are some pcbs underneath the small lcd display, that contain some very small SMD fuses. Fore some reason - bad battery, bad card, power spike, they get blown, and then no power to camera. I already fix a 5D classic having an identical problem. All you need is skill, a set of screwdrivers, multimeter, SMD fuse and soldering iron or station.