Again the Elmo GS 1200 projector

[Antoine Orsero]

my elmo gs 1200 projector works well except for the take-up reel. It turns slowly, sometimes it stops and starts again.
I feel this problem is with the item in the photo attached
Does anyone have an idea?
thank you so much

[Douglas Meltzer]

Antoine,

Occasionally the gear at the bottom of the take up arm splits. Take a look at this thread.

Doug

[Chip Gelmini]

Was that the machine from Bob?

[Paul Adsett]

Quite possibly its the small relay on the main circuit board. It controls the voltage to the rear take up motor.

[Xander van der Merwe]

Here is the section in the service manual that covers the rear take-up arm - hopefully it can give you additional options to look at:

[Antoine Orsero]

Thank you for your answers! Everything you wrote has been checked and there is no problem there!
But I wonder what the small potentiometer N ° 3 is used for in the attached photo. When I touch the trasistor cooler it burns my fingers
thank you so much

[Phil Murat]

Hello Antoine,

I have just sent you an Email.

Transistor(s) Overheat = Too Much Amp throughout circuit
(If you can not stand heat with your fingers , that means T° is closed to 60°C)

I suggest you to :
- Check Motors / Mecanisms spins freely
- Check Brushes and collectors for cleanliness and condition (worn ?)
- Check Brushes size : If too short, worn out , replace them


Bon Courage
Tenez moi au courant

[Alan Rik]

I had this problem a few times and once it was the board with the pots on it. Here is the thread it may help you. https://8mmforum.film-tech.com/cgi-b...=001511#000000

[Phil Murat]

Hello Alan,

Thanks for this very valuable information.

I have just passed an order for 2SC1815 transistors (just in case of.....) , they are cheap....

Did you noticed a power transistors overheat on this board too (impossible to keep fingers on aluminium heat sinks) ?


Complementary "Fault" information :

Antoine's machine shows an intermitent fault, sometime take-up motor runs, sometime not ........

[Alan Rik]

I never checked for heat since I got shocked from a TV that I never discharged the caps to-threw me across the room! So I waited a good few hours till I started poking around in the GS..

[Graham Ritchie]

One option is to do this, I did years ago and have had no problems since.

[Antoine Orsero]

Thank you very much for all your advice.
But it's too complicated for me considering my age and my ignorance in electronics.
I have two broken GS1200s but I have ST1200s which work very well and which are more mechanical than electronic.
My best regards to all
Antoine