Urgent help needed with my 580EX Flash. Shoot on today!!

[robster]

Hi all,

I have part 2 of my 2 day shoot on today (this morning) and at the end of yesterday I had some real drama with the flash unit, I'm hoping someone can offer advice? (It's happened twice now to me).

I have my EOS30D driving the 580EX via cable, the 580 is then driving a 430 which is off to the right. 580 set to master, 480 set to slave.

Worked great all day, I sometimes set the 580 to flash, other times not to flash and when I did set it to flash I used ratios so the 580 was being used as a softer (1/128 power) fill light and the 480 the main light bouncing off the wall (at anywhere from 1/32 to 1/64). It worked perfectly and we got great results.

The problem though:

At the end of the day the 580 started to not respond to my menu choices. I could press the ZOOM button to get to the flash on / off icon choice but spinning the wheel selector, it would not move from on to off. It was the same for everything, I couldn't change ratio's, zoom levels, anything.

I switched the unit off and on, took out batteries, rested it, same thing.

It then started flashing at me (note, only in master mode it did this) and all I could do was change its power (which changed the slave unit to the same settings) and had to finish the shoot with the master pointed well at the back wall.

It made the last shots less than satisfactory, I did what I could, but it was VERY frustrating. I can't have it happen again today.

Does anyone know what this is?! Why would the unit have its display flash at me? and why wouldn't it let me change settings?

Thanks,

Rob