8mm Forum: I Dood It All By Myself I Really Did

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Posted by Chip Gelmini (Member # 44) on October 04, 2017, 07:12 PM:

Today I am pleased to report I have completed my first GS 1200 repair done by myself. It was a minor adjustment. But still, on these machines, any type of fixing requires patience, knowledge, and skill.

The other night I started an optical feature, and the sound was just terrible. There was intermittent rumble in the background. The treble was gone. The sound was very mushy and also lacked bass.

Upon examining the projector while running, I found the film was moving up and down in the bottom right green guide just before the slit lens and exciter bulb. It would move up and be tight and it would move down into the deeper part of the green guide.

I checked two other machines, and spotted the tension spring position was different. In the two checked machines, the spring clip was pointing slightly to the left, at say 7 O’clock position.

At the machine giving trouble, that same spring clip was pointing straight down, as 6 O’clock position.

This morning, I carefully loosened the retaining screw, and gently moved the spring clip to the 7pm position. A quick test of optical sound and BINGO sound is where it should be.

I like running these things but I am not much of a technician.

Except for this one time I guess. Shame to have taken it to a repair $hop just for this one speedbump………………

Feeling a tad bit proud!

Posted by Steve Klare (Member # 12) on October 04, 2017, 07:31 PM:

Well Done, Chip!

I've fixed a lot of stuff: at work, at the house and for hobbies, and there's lot of stress until you turn the key and the thing fires on all cylinders the way it was meant to, then come the endorphins! (Sometimes I miss my old car...my new one just runs without my help!)

I can honestly say about most of my projectors: they are mine, not just because I paid for them, but because I made them work.

Posted by Mathew James (Member # 4581) on October 05, 2017, 08:15 AM:

Nice job Chip. There is nothing like the feeling of success from fixing something, especially on this projector. glad it worked out. Fell free to document in pictures anything that could be helpful for others on the forum as well. Cheers.

Posted by Paul Adsett (Member # 25) on October 05, 2017, 10:14 AM:

Well done Chip! I only have one optical print and it never sounds good, so I will try your fix.
Repairs on the GS are expensive and its always worth trying something yourself first before sending the machine for repair- as long as you don't get carried away! On my two machines I have found that 90% of the GS problems are related to switch problems in the 'piano control' logic system. Those little microswitches seem to be the root cause of many issues such as the auto-threader not working, or the lamp not switching on, or functions working intermittently. Just this week the lamp on my GS was sometimes failing to come on (even though it was preheating ok). I thought the problem was the big lamp relay switch, but I eventually found that it was again one of those little microswitches on the lamp switch assembly.

Posted by Chip Gelmini (Member # 44) on October 05, 2017, 02:28 PM:

Hi Paul

In regards to GS 1200 Optical spring tension adjustment this should help you:

Download the GS1200SERVICE.PDF file.

Upon opening, go to page 26 of 98 within the pdf file

That should bring you to page 45 of the original Elmo service manual.

Once at that page, refer to fig 22 and item #4 (I refer to this as the "spring clip" in my original post.)

This is the adjustment screw that I worked on.

I used a small eye glass repair screw driver to move the clip once the phillips screw to keep it in position was loosened.

This screw provides proper tension for optical mode and when adjusted correctly avoids wow/flutter in optical sound.

As a safety check I ran both optical and magnetic sound test prints to make sure this adjustment for optical was good and also that it did not change pressure to magnetic.

My repair was successful.

As my experience has also noted:

Whenever I have run an optical print through an Elmo projector, I have found better results running auto-load in MAGNETIC position. Once the thread is completed and the machine's power is shut down, THEN and ONLY then do I switch to optical mode.

It also helps to have a magnetic leader attached to the print. As strange as it seems, I have always thought the machines give a better auto-load in magnetic than optical.

Regards

Chip Gelmini

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