I am a little confused, we moved into the new place not long ago and I replaced many of the lightbulbs in the spotlights. Quite a few of the spotlights don't work despite the new bulbs. These lights use the GU10 fitting. Is there a part that I would need to replace other than the bulb itself? I am currently sitting in the "office" room and it is quite dark because I only have one of four bulbs operational!