Flash Error 99

I hooked external flash to my 10D and it worked a few times, but then got the error 99 message and quit working. When I unhooked external flash it works fine. I called Canon and they said get a safe sync and I have ordered a safe sync hot shoe mounted high voltage regulator. Will this fix the problem?

Thanks-

t

You didn't say what external flash you were using, but the reports I read suggest a maximum voltage across the trigger of about 6 volts. That's much lower than some classic flashes of old, including the Vivitar 283 early models and my Speedotron studio lights. I put a low-voltage adaptor on the Speedotron, and I use a Canon 550EX for when I need an on-camera flash with the 10D.

But the usual cause of Err99 is old Sigma lenses that need new chips from Sigma. How is this related to flash, you ask? Well, I discovered the Err99 problem myself using the nose flash. The problem is that the lens will not stop down on command from the camera, which the camera reads as the Mother of All Errors and gives you Err99. Guess what makes the computer in the 10D want to use a smaller aperture than wide open? You guessed, the flash.

Granted this doesn't apply if you are using an PC-connected flash, which the 10D computer won't know about. And it is true that Err99 is the error condition the 10D shows when it doesn't really know what is wrong, but I mention it just in case.

You can measure the voltage across the flash, by the way, by hooking a voltmeter to the center pin and the edge pin on a hot shoe or the center pin and round shell of a PC cord.

Rick "who thinks cause and effect isn't always that easy to figure out" Denney