the projector stopped working the only thing that is working is the projector lamp
found fuse behind switch controls but that was ok
no power to amplifier or exciter lamp
I had the same problem with my own bell & Howell 642.
In my projector a 5W 1000ohm resistor in the amplifier had broken.
Try first to adjust the potentiometer near one of the EL84 tubes, if that doesnt help, try to measure the 5W 1000ohm resistor. Replace it if has gone high. You may need to adjust the potentiometer to make the exciter lamp work.
Atreju
January 2009
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix film projectors.