I'm sure you've done most of these, but just in case:
1 - Double check the wiring diagram
2 - Make sure any unused wires are capped seperately
3 - Check the fuse in the ballast
4 - pull and twist every wire at the endcap connection to make sure it's firmly seated
5 - If any of the bulbs blink, even slightly, then the ballast is fine
6 - If after doing all of the above none of the bulbs even blink call IceCap for a replacement ballast