some help with my 580ex please

i desperately need some help
my 580ex will not work in slave mode
i have changed the batteries,checked all the custom functions,tried the same batteries in the 580 ex2 and that works perfectly
the 580ex will fire in master mode and will set off a slaved 580ex2 and it will fire when used as a normal on camera flash not in master mode
can anybody tell me what is going on

Some things to check...

Make sure that the 580 in slave mode is set to the right channel.

Make sure it is set to a group that is being told to fire (if it is set to Group C, then it won't fire if the master is only instructing Groups A and B to fire).

Can the 580 see the master?

thanks for the response
it is on the right channel
the af assist light does not even blink which it is supposed to do when in slave mode

Is it a mark 1 or mark 2?

The problem sounds like a faulty Off/Master/Slave switch. It may be repairable, or replaceable. If you do not know a friendly instrument techician, try Canon Service.

The wireless select switch, and possibly the contacts pcb assembly may be available, or it may be just a broken wire up to the main pcb. However, the main pcb also gets zapped at times, and seems to lose its firmware programming. That could be uneconomic to repair.

did some more experimenting with my faulty 580ex today and i have to agree with cliveyboy
it seems my 580ex now only functions in master mode
moving the switch from off to master to slave does not change the display on the lcd and the 580ex will set off a 580ex2 set to slave regardless of whether the 580ex is set to off,master or slave
in addition the 580ex cannot be disable from firing
as an on-camera flash it maintains all of its functions
it is a bit limiting since before i had two ocflashes controlled by an st-e2 and now i can only get i flash off camera

Is it under warranty? Methinks you need it fixed or replaced. Give Canon a call, or take it to the shop you got it from.

it's fixable, and the cost to get that done is probably cheaper than a whole new replacement...

thanks for the reply
one small problem though,i am in jamaica and the cost of shipping to the states is probably more than the repair bill