YN565EX speedlight display only SE

Hi,
Yongnuo YN565EX speedlight display only SE and does not flash. After restart of the flash everything comes back to normal, but I may lose a pictures while the flash did not fire.

WHat is the meaning of that "SE" and how to prevent that issue?

Best regards,

I think you have the SLEEP mode enabled (P46 in the manual). Function 1 controls ON/OFF, function 15 controls time before sleep.

Not 100% certain about this but check and see if this is your problem.

I don't have the manual, but I doubt it is the sleep mode. It usually happens after a few consecutive shots (3-4 shots in 30 seconds). Then when I shoot again, the flash does not light up (but the camera is still expecting it to burst, so the picture is really underexposed, even in P mode). I would expect the sleep mode to disengage in that case.

Maybe I am missing something.

few consecutive shots may be the clue? perhaps flash gets overloaded somehow?

manual is located here: http://www.yongnuo.com​.cn …SER_MANUAL_YN56​5EX_EN.pdf