Hi I have a pair of GM 500's and 1 has developed an error.
It's hangs on  ' Chr '  and won't let me select any other function. Sometimes it then goes to  ' Er 1 '
(which I believe is a power problem)

I've checked the flash & Modelling bulbs and they're fine.

Any Suggestions would be great, also an idea of repair shops in the NW if possible.

Thanks