there are 2 types of lighting one is magnetic and the other is,, errmmm balast .. i think, one can be repaired ( that little white starter.. the other isnt so easy ( i found this out when i had a prob with one of my own ligh units ( tho not on a juwel)
post in the DIY AND HARDWARE section.. theres bound to be someone over there that can help...
good luck and i hope you dont have to end up changing the whole unit ( they are readily availible which makes me suspiscous tho )