420 EX beeps on 400D

happyham · 24th October 2006

Took out my 420 EX flash and attached it to my recent 400D.

Heard the usual startup sound and then the thing starts to beep in like 0.5 sec intervals.

The flash can still fire and Canon says that its compatible with the 400D but the sound is annoying.

The thing is that when I switch to review mode the sound disappears but comes on again

when I am in shooting mode.

Have I omitted something? The flashed worked fine on my previous 350D.

sehsuan · 25th October 2006

That's perfectly normal. That's the sound of the charging of the capacitors.

happyham · 25th October 2006

even after say like 5 min?

raptor84 · 25th October 2006

Yes even the 430 ex has a soft beep every 5 secs. Not relaly noticeable. The thyristors are constantly trickle charged.

24th October 2006	#1
happyham Member Join Date: Nov 2003 Posts: 196	420 EX beeps on 400D Took out my 420 EX flash and attached it to my recent 400D. Heard the usual startup sound and then the thing starts to beep in like 0.5 sec intervals. The flash can still fire and Canon says that its compatible with the 400D but the sound is annoying. The thing is that when I switch to review mode the sound disappears but comes on again when I am in shooting mode. Have I omitted something? The flashed worked fine on my previous 350D. Last edited by happyham; 24th October 2006 at 09:09 PM.

25th October 2006	#2
sehsuan Deregistered Join Date: Dec 2002 Location: Singapore Posts: 6,674	Re: 420 EX beeps on 400D That's perfectly normal. That's the sound of the charging of the capacitors.

25th October 2006	#3
happyham Member Join Date: Nov 2003 Posts: 196	Re: 420 EX beeps on 400D even after say like 5 min?

25th October 2006	#4
raptor84 Senior Member Join Date: Dec 2005 Location: Singapore Posts: 4,282	Re: 420 EX beeps on 400D Yes even the 430 ex has a soft beep every 5 secs. Not relaly noticeable. The thyristors are constantly trickle charged. __________________ Pet Portrait Portfolio Stock Photos for sale