Hi All –
Over the last few days, my 5d mk ii started getting an intermittent error after taking a shot where it would say:
“Err 70: Shooting not possible.” The next shot would be fine, so I dismissed it as probably a card that needed reformatting.

Yesterday, I reformatted the card, charged the batteries and it seemed fine.

By last night, the error was popping up more frequently and by the end of the evening, it was requiring me to pop out the battery to get it to wake if the camera went to sleep.
This morning, it seems dead.

I tried two different batteries, both with the battery grip and without.

I cleaned the lens contacts, but I don’t think it was that, as I’d get the same behavior with different lenses or with just the body cap on.

I tried different memory cards and with none, as well. Same thing.

I have it sitting with the battery out and the backup battery out (the coin battery) in hopes that this will get it to revive and if it does, I may try to re-install the firmware.

Has anyone come across this? Google brings up scant and conflicting answers, the most likely being “a CMOS error.”

If that’s the case, how big a deal is that to get fixed? (There’s a Canon service place here in Tokyo, at least.)

The thing is, this is the camera I do my work with and my backup (old 5D) is on loan to a friend who just went to shoot a project out of town for a week.

Anyone know of a quick fix or some kind of reset or something?

Thanks in advance.