Both my Arrihead and O'Connor 120 EX head need to be serviced after a very dusty show. Does anyone know a good resource in Los Angeles that can work on both? Someone told me that their guy wouldn't work on the 120 EX (as opposed to a 2575) for some reason, so I don't know if that is possible. It is the first time I've needed to have either serviced since I bought them so I'm a bit in the dark - any recommendations are appreciated. Thank you in advance for the help.