I was doing some printing with one of my Super Chromega Dichroic II D equipped enlargers yesterday when the main bulb suddenly quit. Burnt out bulb was my assumption. Changed to a new bulb, still no light. Swapped in the power supply and timer from my other Super Chromega Dichroic I D enlarger, which works just fine, and still no light from the first enlarger. On the first one, the problem appears to be in the head itself, and not with the power supply, timer etc. The fan motor will run, but no light. Is there a component inside the head, such as a fuse or something, that also needs to be checked or replaced ? Appreciate any insight and guidance.