I had the same issue and repaired it by taking the thing apart and putting it back together. I found the center tap on the power transformer was loose. The build quality of this thing is terrible. Re-seat all the connections and you might fix it.

Low volts causes the fan to turn slow or take a long time to start. The lamp is interlocked to the fan. Spin the fan by hand, it should rotate freely. If not, find a substitute fan from digi-key.

Check flea-bay, I got my manual for $5.