change the bulbs first that useally take care the issue but just watch out on 150 watts verison there are two types of them one them is 55 volt and other one is 100 volt verison.

so check the ballast little more closer to see if it say " 150W/55V or 150W/100V

The other thing is the arc tube length the 100 volter have longer tube than 55v verison

Quick note here any 150 w med based bulb are 55 volt only but on mogual based bulbs it can go either way so pay attetion to this details.

Merci,Marc

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)