high pitch beep from a 580ex?

[kenwood33]

Just bought a used 580ex. I notice that it beeps every 3-4 seconds while its turned on. The beep is a very high pitch sound. You have to put your ear near the flash in order to hear it. Is this normal?

[BradT0517]

Yes this is perfectly normal. It is the sound it makes when recharging the capacitors.