Switched out a simple 2' one tube utility strip fixture over the kitchen sink with a two tube (F20T12/cw) T12 120Vunit. Reconnected black to black, white to white, and bare ground wire to the green screw on fixture. Ballast is 120v 6hz .054A electronic. When I flip the wall switch, the tubes try to light, then cut off and won't come on again. The power supply coming in is within 1/2 in. of ballast. What's up? Thank you for any suggestions.

Sounds like a bad fixture. Check your wiring connections... check the bulb holders.