i have a canon flash 580ex ii
when i press the <High Speed Sync Button> on the flash NOT see the Lightening Bolt and the letter "H".
my camera is 7d.
i insert fresh batteries into the flash and attach it to the camera ,Turn on both units and verify that ETTL appears on the flash's LCD , but when i press High Speed Sync Button . nothing happen only see low speed sync,
the Custom Functions only is 00-0 to 01-1 , no change to 02 03 04.
can i program the flash with pc ?
or what i do ?