Is there a light that can replace an old Pac Fab Hatteras Pool Light

I have a old Pac Fab Hatteras Pool Light 120V 500W

For whatever reason the light doesn’t work, I can tell it has power, the bulb is brand new, yet it doesn’t turn on.

I have pretty much given up and just want to replace the whole thing.  Is there anything that can replace it but fit in the same shell?