430EX E-TTL not working - Is it completely bust? is it fixable?

[davemmm]

I've just gone digital and upgraded to a shiny new EOS 40D. I was trying it out with my 430EX, and it was

producing beautifully exposed flash shots with E-TTL II.

Without warning though I started getting big flashes and dark muddy pictures when I pressed the shutter button.

It appears that when the E-TTL pre-flash should be firing, the flashgun is dumping all its power into the tube, and

then having nothing left for when the camera needs to fire the second flash burst to illuminate the actual exposure.

 

I tried resetting all my 40D settings in case I'd changed a setting somewhere that I didn't understand. It's

definitely a problem with the 430EX as the same problem occurs on a 400D and a 30E.

 

Searching through the archives, some other people have had the same problem, but it doesn't seem to have been

resolved.

There's definitely communication between the camera and flashgun as the 430EX is displaying ETTL in the LCD,

adjusts the zoom of the flash with the lens, and displays the icon which shows it knows it's on an APS-C sensor body.

 

I've tried rubbing the flashgun contacts with the eraser on the end of a pencil, so I don't think it's a dirty

contacts issue.

 

So...

 

Has my new 850GBP camera bust my lightly-used 199GBP flashgun and fried the electronics to a crisp? Is there

anything I can do to fix it myself? Is this something Canon UK can fix for a reasonable fee?

 

Thank you in advance for any help or advice - I'm very upset at the prospect of being stuck using pop-up flash

(or as that's not very good, no flash) until I can afford to replace my flashgun, which won't be for quite some

time given the financial drain of my new 40D.

[mark u]

Presumably the flash is still within the warranty period. If that is the case, I suspect if you send it in for repair Canon will replace it. Perhaps you should test it in other modes, and make sure that you have clean flash contacts on the camera and flash. It may also make sense to verify that there isn't a problem with the camera by trying another flash that is known to work properly.

[davemmm]

Unfortunately I bought the flash in 2005, and Canon only do a one year warranty.

 

Has anyone had this fault repaired? I don't have the ability to reduce the flash power in manual mode either, so

it would seem the circuit which controls flash power is busted.

[mark u]

I could have a guess at the component(s) that might have failed given the symptoms you report, but I think that Canon simply replace whole circuit boards if they will do a repair at all, even though the failure may just be a component costing a few cents (although its failure might result in other components being overloaded, spreading the damage). Here is a description of the type of circuit typically used to quench the flash:

 

http://www.repairfaq.org/sam/strbfaq.htm#strbvi2

 

You might as well ask Canon what they can do for you. With the Mk II version of the flash just announced, perhaps the original 430EX will be available a little cheaper, both new and second hand: at least it isn't quite as expensive as when you bought it.

[mark u]

Someone evidently had some joy getting Canon to fix a flash:

 

http://photography-on-the.net/forum/showthread.php?t=297656

 

Be sure to compare the cost with a replacement though.

[davemmm]

Thanks Mark. I've filed a tech support case with Canon UK, and should get a response early next week.

I wouldn't be surprised if the cost is parts and labour for a whole circuit board, but if it comes in around 50 to 60GBP, that's still a saving over the 170GBP cost of a new 430EX.

 

I'll update this thread with my progress so that it's useful for the next person with this problem.