I have a Durst L1200 enlarger with a CLS500 color head with a problem. I noticed the light was very dim when i got it, requiring very long printing times. I looked at the bulb and compared it to what I found recommended in the manuals for the CLS 501 head. My bulb is a 200W, 84V bulb and the manual says a 250W, 24V bulb. So I got a couple of the recommended bulbs. They both immediately blew. It only took a second or less and they were gone. I checked the fuse in the transformer and it is fine. It is a 250V, 5 amp fuse as per the manual. I also noticed that all the little bulbs for the filter dials are out, but do not look damaged. I do not see a switch for these or any reference to a switch in the manual. I appreciate any help from those of you that know these enlargers or electrical wiring.