CDJ 900 Won't Turn On

I have 2 pioneer CDJ 900 that are barely used. As of recently they won't turn on occasionally. I took them to a certified repair shop, charged for looking at them only to be told they work perfect. WhIch they turned on fine there. At my next gig they both turned on, then I turned one off to reset it and it would not turn back on. Now testing before my next gig they both won't turn on. I can't seem to find anything in forums regarding this. I have tried different power sources, cords turning upside down. Everything. Any help or guidance would be greatly appreciated.