Canon EOS 5D Instruction Manual page 229

Display & Operation Problems
The LCD monitor does not display a clear image.
If dust is adhering to the LCD monitor, wipe its surface with a lens cloth
or soft cloth.
In low or high temperatures, the LCD monitor display may seem slow
or might look black. It will return to normal at room temperature.
Few tabs and options are displayed on the menu screen.
In the fully-automatic modes (1/C), some tabs and options are not
displayed. Set the shooting mode to <d/s/f/a/F> (p.40).
Part of the image blinks in black.
The [4 Highlight alert] option is set to [Enable] (p.145).
A red box is displayed on the image.
The [4 AF point disp.] option is set to [Enable] (p.145).
The image cannot be erased.
If the image has been erase-protected, it cannot be erased (p.159).
The file name's first character is an underscore ("_MG_").
Set the color space to sRGB. If Adobe RGB is set, the first character
will be an underscore (p.76).
The file numbering does not start from 0001.
If you use a card which already has images recorded, the file
numbering might start from the last image in the card (p.74).
The shooting date and time displayed is incorrect.
The correct date and time has not been set (p.42).
Troubleshooting Guide
229