Looking for some ideas.

My month old 580EXII does not seem to sync on the 5D2 in E-TTL II mode. Works fine if I set the flash to manual as well as TTL. Does the same thing with fresh batteries, on camera or with the off camera cord - flash fires and does not appear to be a full power. Funny thing is that it just 'stopped' working right in the middle of a shoot. The contacts look good on both the foot and the shoe, the camera still seems to talk to the flash thought the menus as well. Does the same if I shoot in M or Av, will have to try P but I doubt it will be different.

The camera/flash/sync works fine with my older 580EX in E-TTL.

Any ideas ? Is it pooched or is it me ?

Thanks.

Some additional info experiments - in case it help anybody with their guesses...

Flash is displaying E-TTL
FEL produces a full power pre-flash
Does the same thing on a 20D
If I setup a scene with only the need for fill flash - flash on or off does not make a difference.
Works / sync's fine with the flash in Manual or Auto External.

I am now guessing something went south with the E-TTL circuit board so that it does not see the pre-flash or misses sync. It might be one of the contacts though.

I guess I will take it back to where I bought it and hope for an exchange. At least I bought it from a local reputable retailer that I deal with often. I have to shoot a wedding in a few weeks as was planning to use this as my main flash. I will probably use my only 580EX as primary and the 580EXII replacement as backup. Funny things is that I would be doing the formals with the flash set to manual in most cases - only for candids would I have needed E-TTL.

If controls are set correctly they usually work correctly and if not are defective. Since it quit in the middle of normal operation signs point towards nearest Canon repair facility.

Since you also have a 580ex you might try it as Master with the 580exII as slave and see if E-TTL mode works.

FWIW - I have seen a few reports of circuit board problems on the 580exII. The EU requirement to eliminate lead from solder requires the use of more brittle formulation so cracked/loose connections are more of a problem than in the past.

You wouldn't every want to set the flash to TTL mode. That is a legacy film mode which causes the flash to fire at full power waiting for the "off" signal from on-film metering that never comes when used on a digital. The most frequent complaint with the 580exII is changing to TTL randomly due to contact problems.

ETTL-II evaluative measures the ambient vs pre-flash to determine flash power needed. In some situations where the ambient light is very bright or the ISO is set very high the flash won't go off or contribute much because the ambient is adequate, even when the camera is in M mode.

Chuck

Tried some experiments with master/slave.

580EXII in master mode did not fire the 580EX. No pre-flash, no test fire, zip...
580EX as master did fire the EXII but the EXII looks to be putting out full power all the time. Even the preflash - FEL press - if full power - still seeing spots any ways.

Hopefully, I can exchange for a new unit as I doubt I have time for it to take a trip to Canon service before the weddings.