I have a Hampton Bay ceiling fan which uses a circular 9 inch fluorescent bulb. Lat week the light no longer worked so I bought a new bulb. No luck.

I was under the impression the ballast for these types of bulbs was in the bulb. Anyone know if there is something else I should try as opposed to a new ceiling fan?

Many Thanks

Possibles causes:
Bad Replacement bulb, Can you test in lamp?
Someone pulled chain and/or switch wall switch settings.
Will regular bulb fit socket for test?
No need to repkace fan for light problem.
Usually Ballast is center of Bulb assembly.

These fans are notorious for bad ballasts. Return it to Home Depot.