Aquarium Metal Halide's taking hours to come on, why?

Here is the scoop, I bought a 2 175 watt Metal Halide/4 65 watt pc light system from ebay (used). The guy said he just replaced the bulbs and are brand new and they came on once he installed in. However, he said that when he tested again they didn't turn on but after awhile of flicking on and off on the electric ballast he was able to get one on. I now have this 48" light system and I have it plugged up to a 8 socket surge protector. One light came on after flicking it on and off the other one didn't. I left the hours for approximately 4 hours and when I came home they were both on. I of course turned them off when it was nights out for the fish now the next day I cant even get any to come on, it's only been a hour and I still see no action. My external ballast's are rated 175w and so are the bulbs. All other pc lights and moon lights come on with a flip of a switch.