Canon 5d Mark II Parts Lists and Schematics
Same - just stopped working.
I came up with a blown fuse - they can be purchased on-line for a few dollars. Not much help I know. Then you have to solder it across the top of the blown SMD component - or remove the old first...
Easy enough to get at, but a bit fiddly.
Part Number - VD7-2293-001
dpreview - 3rd party batteries blow the fuse easily - apparently.