Akai s900 - Heeellppp!

Heres the problem, I've had an s900 for over five years now. It works fine,until I want to midi it up to my XL. Every time I try to midi it up, it turns off. No power, nothing, just turns off completely. Takes at least 20 minutes to turn back on. If I just use it to sample and not use midi, I can leave it on for days. I'm figuring it has a bad midi connection or something of that sort since I only have problems when connecting to my XL. The midi ports worked before and it would be hours and hours before it would shut down. any suggestions or ideas? maybe a reputable repair shop in the southern CA 909 area. thanks[/color]