Recently enlarging with a V35 leitz enlarger and the bulb went out. I first thought that it was a blown bulb. Tried new ones, still no light.Secondly I thought it was a blown fuse. Upon inspection of fuse, that doesn't seem to be the case. Checked the switch on the base: it was set properly. The outlet has power. Could it be a blown transformer without a blown fuse. Never happened before with this enlarger. If it is a blown transformer is the next action throwing it out? That would be a shame. Any other steps I should try?