420EX fires only pre-flash (at full blast?) and does not expose actual picture

Hi everyone!

I have trouble with my new-acquired Canon Speedlite 420EX, which I wanted as a

cheaper replacement for the 430EX. But the flash unit seems to be not working

correctly, so I need your help to see if I am missing anything or if the flash

needs to go to Canon for repair ($$$)...

 

The flash seems to be in order, batteries charge the thyristor, the pilot light

and "E-TTL" light up, even the AF assist looks okay. But when I actually take a

picture, the flash fires a very bright pre-flash and is then not exposing the

actual image -- there is no second flash and the strobe seems to recharge for a

couple of seconds. I am under the impression that the 420EX fires the E-TTL

pre-flash at full charge and has then not enough power for the real image. This

odd behaviour even occurs when I use FEL, let the flash recharge and take the

picture after a couple of seconds -- it does not fire again and the asterisk (*)

disappears shortly after I pressed the FEL button. FEC also never lights up.

 

I checked every setting on the flash and camera and nothing seems to be wrong. I

use the flash not in slave mode, just mounted in the hotshoe. Direct or bounce

flash, regular or high-speed sync, or the various program/mode settings (P, Av,

M etc) do not affect this issue. And yes, I did clean the contacts and tried

different lenses. Any ideas what might be the problem -- maybe I am missing

something obvious, having used a simple 380EX most of my Canon time?

What camera are you using?

 

Also, have you tried the flash in full manual mode, does that work OK?

Sorry, I am using an EOS 20D. The 420EX itself has no manual settings, and with the camera on "M" this behaviour is the same (only pre-flash, no flash light on actual image). I can also fire the flash by pressing the pilot light, but obviously this isn't helping anything.

Does sound like a problem, I wonder if S/h the shoe has been rewired incorrect, did it ever work at all? can you return it?

Also is the shoe tight on the 20d? I`ve had problems when the shoe gets loose on mine.

Chris, my other flash units work fine. The hotshoe is tight. I bought the 420EX used, maybe the seller was dishonest, maybe I am doing something wrong. Later today I will check it on another camera, but for now this issue really puzzles me.

That 420 should behave like the 380. Do you still have the 380EX to try on? Looks like you have a defective unit.

I use the 420EX on a 20D. You may have a defective unit but just to be sure here's a few things you can try.

 

1. The 380EX cannot be a slave so on the 420Ex is the Slave switch located low on the back towards the hotshow set to OFF?

2. Have you new batteries in everything?

3. Is the Falsh pushed all the way onto the hotshot with the lock-pin engaged?

4. Are the switchs on the side slots of the Flash clean and protruding?

5. Are the swttches in the slide of the hotshoe on the camera clean?

6. You should not be in hi-sync.

7. Are you using it in P mode? Av is for fill-flash

8. Are you waiting for the Pilot light to light up?

9. Do you see the Flash icon to the left in the viewfinder?

10. In P mode does the shutter automatically get set to 1/60th?

11. Does the ETTL light and a distance light come on at the back of the Flash

12. Is C.Fn-03 set to Auto?

13. Is C.Fn-05 set to Emits?

14. Is C.Fn-07 set to Fires?

15. I use C.Fn-14 set to Average

16. Is C.Fn-16 set to 1st-curtain sync?

 

Best of luck, it is a great Flash unit so hopefully you can get it working without too much bother.

Peter: 1-yes; 2-yes; 3-yes; 4-yes; 5-yes; 6-tried both; 7-tried it, I know; 8-yes; 9-yes; 10-yes; 11-ETTL and focal length light up; 12-yes; 13-yes; 14-yes; 15-makes no difference; 16-yes.

 

Looks like the flash indeed defective. I tried it on a different camera with the same results. If someone has a similar experience I would happy to learn more about.

Bueh: I had the identical problem in the spring of 2003. My 430Ex had been working fine for 2 years on my film EOS. I added a G3 and it worked fine for a few months and then stopped working in the identical manner as you mentioned.

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I submitted the unit to Canon who fixed it twice in that year alone. Recently, the same unit has failed with the same symptom. The first time it was fixed the cost was CAD$75 (They reported: replaced the main circuit board). I'm debating fixing it or upgrading to the next model or a sigma Flash.

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In terms of use, I was using the flash as a slave in my system. It was not heavily used in the least, a few hundred shots in the year I'd estimate.

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I've been toying with the idea of opening it myself and trying to fix whatever is damaged in there. I suspect I know what is wrong, but can't seem to find the time to actually open it up. If I do, I will certainly post to this group.

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Sorry I could not offer any better information. If you search some of the other photography forums, you will find an almost identical question posted by myself to see how widespread the problem is/was. I did not receive much feedback however.

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Good luck with the flash.

Thanks Brian. If I could open it, I would too take a look and see if there is something obviously wrong. Since the flash is working almost correctly, maybe it is indeed some wiring or loose contact issue. What do you suspect is the problem?

 

For now I try to get a refund. I hope this turns out well.

Just to clarify my previous post. My flash was a 420EX and not the 430EX which I posted. From the symptom of the problem, I am suspecting the problem is the a faulty/burnt-out diode or thyristor. Because I have a backup flash, I'm not in much of a rush to fix it. However, I am also not willing to have it fixed again.

I had sorta similar problem with mine recently and e-mailed the customer service at Canon. Here's their response. I haven't tried any of these yet, but will do as soon as I'll get home:

1. Remove the batteries from the camera.

 

2. Take a clean pencil eraser and gently rub the contacts on the bottom

of the battery compartment. Tilt the camera slightly so that any

particles are able to fall out of the camera.

 

3. Replace the batteries and power the camera on. Make sure that the

batteries are fully charged if using NiMH or new if you are using

alkaline.

 

4. Use the pencil eraser on the mounting foot of the Speedlite and hot

shoe of the camera to ensure that there is good contact being made

between the flash and camera.

 

Try the flash with the camera again. If they are still not synching up,

reset the flash and the camera.

 

To reset the flash, remove the batteries from the flash and allow it to

sit for about twenty minutes. This will reset the flash.

 

To reset your camera, please follow these steps:

 

1. Set the camera to one of the CREATIVE ZONE modes.

 

2. Press the MENU button.

 

3. JUMP to the yellow SET UP menu.

 

4. Scroll to the CLEAR SETTINGS option and press SET.

 

5. Select CLEAR ALL CAMERA SETTINGS and press SET.

 

6. Select OK and press SET. You will then return to the menu.

 

7. Select CLEAR SETTINGS again and press SET.

 

8. Select CLEAR ALL CUSTOM FUNCTIONS and press SET.

 

9. Select OK and press SET.

 

Try using the camera and flash again. If the issue does not repeat then

it has been resolved. If it does repeat, then the flash will require

service.

 

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