Anyone have any experience with the Hayward Colorlogic Generation 2.5 light not working?

Worked fine when I opened the pool...... had it on 2 nights ago.....went to turn it on last night and nothing!

Friend of mine is an electrician so he came out today and we checked the switch (which is mounted in the house) I thought for sure the switch had gone bad with all of the turning off and on to change shows but switch was good.....we still replaced it with another. Power is still good to the switch also.

Is it possible the bulb burned out? Unit is just about 4 years old. Does replacing the bulb (or unit) require that I drain the water level to below the light?

Any input would be appreciated.