No announcement yet.

Bolex SM80 Programmatic problem

  • Filter
  • Time
  • Show
Clear All
new posts

  • Bolex SM80 Programmatic problem

    I have had this machine for a number of years as a back up projector. After several years of none use, I took it out of the cupboard today to give it a try and it is totally dead. There is nothing at all. No fan noise or any sign of life. The power lead works fine on my Eumig, so I know that's okay.

    Any ideas on what the problem is would be most welcome. Thanks.

  • #2
    Hi Gary,

    I'd say something pretty fundamental is going on here, like a blown main fuse or an open-circuit power connection. I have an SP-80 Special, which is a pretty close cousin, and when I plug it in I expect to at lease get the fan and the lamp on low intensity.

    If you are skilled with a multi-meter, you can set it to Ohms and probe between the two power pins on the plug (unplugged: after all you have to to make the measurement anyway.). If everything is connected between the plug and the transformer primary, you will see very low Ohms. If the fuse is blown or a power connection lost, you will see an open circuit.

    If you find a blown fuse, that's probably not the end of the story: sometimes fuses blow because they are old, most times they are the victims of some short circuit deeper inside the machine. When designers choose things like fuses, they usually allow for multiples of normal operating currents before the thing actually blows: it saves a lot of calls to Customer Service by angry customers!


    • #3
      Hi Steve,

      I have little or no electrical skills.

      Suspecting a blown fuse, I took the back cover off and could see only one fuse, located at the bottom front area. It is marked as 2AT and looked fine.

      I can't see any other fuses at all.

      I will try and get hold of a multi-meter to do what you said. Many thanks.


      • #4
        Whatever you do, do it unplugged! Line voltage everywhere in the world is enough to kill! (You might say it's one thing we all have in common!)

        A continuity tester would do the job too, you just need to stay well below 2 Amps to avoid blowing that fuse even if it is actually good.

        Something to try is to look for things like lugged connections in the wiring: given enough time they can build up oxides and go open circuit. Very often if you slide the connection back and forth on the lug you can break the oxide film and bring the thing back to life. Since these are often used for things like line voltage selection, it's important that they finish on the same lugs where they started.

        On many projectors, I'd be suspicious of the main switch, but these are different: the fan and lamp power up whenever you plug in and the main switch can't stop that even if it is bad.


        • #5
          The only fuse in those projectors are for the amplifier. the motor is unfused. do you perhaps have a little switch on the back that is on the zero position? you may overlook that one as only the high end projectors have that (useless) switch. it also blocks the main selector


          • #6
            Steve - I'm quite electric phobic and always double check that anything is unplugged. Thanks for your help with this but Erik solved the puzzle.

            Erik - thanks, it was the little switch at the back that was on ZERO! I have no idea what that switch is for or that it could kill the projector stone dead. Who thought of that idea?!!

            Feel a bit stupid now but because it didn't even power the fan, I immediately thought it was an internal problem.

            Just glad it still works.

            Thanks again Steve and Erik


            • #7
              I've heard of people adding power off switches on these because they don't like the fan and lamp being on whenever it's plugged in.

              I usually run with two machines at once and twist the inching knob to close the shutter. That way the light from the idle machine isn't reducing the contrast in the other machine's picture.


              • #8
                I've just realised that the number of years I've had this machine is actually over 40 and I had no idea about that switch until today!

                In my defence, I've hardly used it in all those years (I stuck with my Eumig S810D) and I only got it out today because the Eumig's speed is going a bit dodgy (done some treatment of the rubber spinning plate things which has made some improvement but will need repeating, I think) and I want to try doing some digital transfers.


                • #9
                  The later Eumigs in the 900 series had a mains switch, I assume this Bolex was manufactured by Eumig and that is why they fitted it.


                  • #10
                    It is a Eumig: basically an 800 series with a different side cover and paint job.

                    This was my first sound projector almost 20 years ago: I got it when I found out about Derann.


                    • #11
                      Yeah, it's definitely produced by Eumig.

                      It's crazy but I never really took much interest in my machine, keeping it stored away for much of the time I've owned it. I obtained it from a fellow cine guy in the late 1970s who let me have it for £20. Yes £20!! Even over 40 years ago, that was peanuts for this projector.

                      Because my Eumig was working perfectly well, I never saw the need to use the Bolex and I probably only ran a short or two through it over all those years.

                      Also, I'm wondering about whether I can run regular/standard 8mm on this Super 8 projector? The super 8 gate and sprockets can be removed just like the Eumig, so if I change them with the reg/std 8mm one's from the Eumig, will it then project reg/std 8mm (sound out of sync, I presume)? I'm only asking because I don't have any junk reg/std 8mm film to risk testing.


                      • #12
                        No, you can not run standard 8mm on this machine. Even though the sprockets and gate can be changed out for standard 8 ones and the soundtrack selector can be switched to track two where the standard 8mm sound track will be located. Unfortunately the claw is dedicated to Super 8 only. That means the Bolex pull-down claw will have two pins instead of one that is used for dual guage machines. Now, if you changed out the claw mechanism with one from an 800 series dual 8 machine you could theoretically play standard 8, but as you pointed out the sound would not be in sync, nor would there be any possibility of ever getting it into sync because you can't adjust the lower loop on this machine to be longer because the auto-load mechanism will always be in the way and can not be bypassed. It would however be fine for silent standard 8mm. But again this creates another problem where all your standard 8mm would have to be respooled onto Super 8 reels due to the supply reels Super 8 only spindle.


                        • #13
                          Thanks for the very comprehensive reply Joseph. Looks like it's staying Super 8 only then!


                          • #14
                            Yes i have no clue why they added the power switch onto the higher end models of the 800 range at Eumig (824) or bolex (sm80), they switch off the motor and block the main selector. all of the other 800-ish models eumig made, for bolex an revue too; that switch wasn't put in but there was a small plastic plate in that hole to cover it up. so it may have been something that was planned and ditched and somehow to be found usefull in the most expensive high end projectors. the 900's also have such a switch but they are allways there. and the system of the motor running as soon as it is plugged in was used from the mid sixties to the end of the 70's so it worked fine without. it may have something to do with something manufacturers do often, put gadgets in there and sell it as a renewal of a model. this is a way to keep consumers happy because they think they buy a brand new developed product as in reality you buy the exact same thing in another housing. (such as eumig's 600 range, the 624 is the 80's restyle of the 610 and is the same projector)


                            • #15
                              Similar to a Eumig 824 but no STD 8mm. You do have 800ft spool capacity on the Bolex and just finished converting it to HID lighting for a customer. Bonus is it has a 2 pin claw as well :-) which runs a treat a great light weight machine powerhouse.