Have Canon 5D Classic that I left on. Drained batteries. Replace Date time battery and recharged batteries. Removed grip cf card and lens. Changed lens cf card and put in batteries. Still will not turn on. I am wondering if batteries or the mainboard could be bad. Any help would be appreciated.
Recently I've seen another post on a different forum for the same problem on a 550D, No one has yet managed to come up with a solution to fix it either. You may have to send it to a camera repair centre to get it sorted
If the charger is showing the batteries charged then your camera should also see a charge on the batteries. Even if the battery is almost shot, you would normally see some sign of life. I do recommend using canon brand batteries if possible as sometimes the camera will not respond to 3rd party ones I have noticed. The other question/suggestion i have is related to grip. You mentioned removing the grip so I assume you tried a charged battery in the camera without the grip on to ensure the grip was not the issue? All this being said, it does seem quite possible your 16 year old camera could have died, maybe canon tech support has an idea for pulling it back from the dead considering it was working fine before the batteries were drained all the way.
Would he need to re install the original battery flap if the grip is removed? Some cameras will not power on of the battery flap is not closed. Just a thought.
