This is a follow-up to an earlier thread where I reported a problem with extreme underexposure compared to the built-in flash when using my 580EX Speedlite mounted on my XTi. Since several others were experiencing somewhat similar problems, this might be useful information. The status of the repairs was listed as completed on the Canon website so I contacted Canon support to find out what was done. I was able to get a brief synopsis and was told that that there would be a detailed report included with the paperwork when the camera and flash are returned.
The initial report is that the flash tube assembly and associated electronics were replaced in the 580EX. This sounds like most everything except the plastic housing
. On the camera itself, there was some repair work done in the upper body and some components replaced along with cleaning the body.
I am expecting to receive the camera and flash today or tomorrow by Fed-Ex so I will be able to provide more details later and, hopefully, see a big improvement in the results when using the Speedlite with the camera.

