It looks like the initial pulse required to create the plasma in the tube isn't working, instead you just have arching between the electrodes not an even plasma. It is most likely a ballast issue but could be due to a bad bulb where the seals have leaked. Try another bulb, if that doesn't work try a new capacitor, if that doesn't work... but a commercially constructed ballast because yours is fucked. Also check your wiring, you may have a bad connection, make sure your not using those weather proof wire-nuts, they have a silicone gel inside that causes more harm then good and creates a bad connection. Hope thats helps...

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