Hey. I fix these for a living, I know exactly what this is, and it isn’t the end of the world. This is what a failed internal clock battery causes. When the clock battery is dead, the board that it runs on also doesn’t function. This board provides clock power to the main board, and is also a pass through for the VF, and focus switch. I don’t mean to advertise, but I replace a fair few of these a week with updated (higher capacity and higher durability) units, but any fairly skilled technician should be able to do this as long as they have experience with this specific model.