Hid bulb help

[Shinotheweevil]

Hey guys, so my hid bulb blew out. I bought new ones and replaced them, which was working fine. But today when I turned on the car the passenger side isn't working again. I switched the bulb with the driver side and the bulb works fine. I also checked the fuse and that is fine as well. Is it the ballast? Can I try anything else to pinpoint the problem?