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Topic: Weird GS1200 issue

Dino Everette
Phenomenal Film Handler

Posts: 1535
From: Long Beach, CA USA
Registered: Dec 2008

posted February 21, 2018 11:58 PM

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I have a GS1200 that is experiencing a weird speed issue, and I am curious where to look for a solution...Basically when I turn the machine on to watch a film the motor going forward either makes no movement at all or is dead slow, probably around 12 fps...If I hit rewind it is either full on 24fps or nothing at all, no movement.....I can run it for like an hour and then it seems like it will run at the proper speed and I can then watch a movie, but there is always the chance that if I stop the machine it might repeat the no movement issue...Once warmed up it will generally either go full speed 24fps or no movement at all....I have other GS 1200's that have a million other issues but the motors always start right up full speed. It reminds me of why I veered away from the ST-1200 with that slow start up....

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"You're too Far Out Miss Lawrence"

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted February 22, 2018 01:05 AM

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Dino

Try giving the ESS switch a good work out when the fwd is pressed and see what happens same for the 18/24 switch.

Another thing I came across with my spare GS1200 was I could not get 18fps... 24fps yes that was ok but not 18fps. It kept running a 6fps I found by giving the relay directly below the flywheel, a bit of a wiggle, that brought it back to 18fps...might be the contacts or a dry solder joint where the relay teminals go through the circuit board not exactly sure, but I am not game to touch it at the moment

Every thing speed wise is running fine now, but there is a lot to be said, for what fellow forum member Thomas did by replacing the motor and its contol...food for thought [Smile]

[Smile]

Anyway best of luck Dino, keep us all informed as to the outcome and hopefully someone else here can contribute with more help

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

posted February 22, 2018 02:27 AM

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I have found that the GS-1200 does tend to be affected with dry joint problems, more so than other projectors in my collection.
I can't imagine that they were poorly made, was it constant use in their former lives?

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Maurice

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Antoine Orsero
Master Film Handler

Posts: 374
From: marseille france
Registered: Jun 2003

posted February 22, 2018 10:41 AM

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I had several GS1200 projector and most had electronic problems. I think these projectors are too sophisticated which makes them fragile! The ST1200 is simpler and more solid!

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Tony

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Chip Gelmini
Phenomenal Film Handler

Posts: 1733
From: Brooksville, FL
Registered: Jun 2003

posted February 22, 2018 04:58 PM

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I had a slow down issue just a few days ago. Messing around with the machine I suspected the “still” switch to be sticky. Contact cleaner worked well and it appears fixed but only time will tell.

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Bill Brandenstein
Phenomenal Film Handler

Posts: 1632
From: California
Registered: Aug 2007

posted February 22, 2018 09:25 PM

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Of all the things! Sorry to hear, Dino. Contact cleaner sounds like a quick and easy stab at a solution. But of all the GS problems I've seen, this isn't one of them. (Knock on wood!)

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Thomas Knappstein
Expert Film Handler

Posts: 124
From: Erwitte, Germany
Registered: Oct 2017

posted February 25, 2018 02:06 AM

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Hello at all!
One of the biggest Problem for Speed Problems in the GS Machines are three little Diodes which are in line with one Main Motor Cable. They have 1 Ampere and the Main Motor need about 750-850mA when everything is fine. If there is less Grease on some Points the Motor need over 1 Ampere and the Diodes are running very hot and soldering out. Than the Motor stops or run slowly. Now I have replaced this three Diodes and changed them for a 5 Ampere Type under the Main Board. Now I can feel it with my Finger when this are going to hot and than its Time to greasing up the importand Points. Sorry for my bad english but i think some Photos will show whatI mean.

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Renzo Dal Bo
Film Handler

Posts: 70
From: Mogliano Veneto, Italy
Registered: Dec 2016

posted February 25, 2018 06:46 AM

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Thank you Thomas! A very precious suggestion here!

Probably to better locate the diodes, in their original position, you have to substitute the first photo with the following one:

[ February 25, 2018, 09:39 AM: Message edited by: Renzo Dal Bo ]

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted March 01, 2018 01:44 PM

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Thomas or Renzo

Looking at those diodes what is the voltage or type number. The ones I can get locally are "ZR-1050...fast...100V..3A..Type FR302"...or FR307....also fast but 1000V...3A ...ZR1052.

If you could give the exact details of the diodes that would be great

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Renzo Dal Bo
Film Handler

Posts: 70
From: Mogliano Veneto, Italy
Registered: Dec 2016

posted March 01, 2018 03:02 PM

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The original diodes from the Elmo GS1200's circuit diagram are 1S1887 type: 400V - 1.0A.

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David Fouracre
Expert Film Handler

Posts: 123
From: Staffordshire, United Kingdom
Registered: Aug 2013

posted March 01, 2018 03:37 PM

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I had a motor fault on my GS1200 which produced a pattern of motor stop, motor running slow and then running normally for several minutes.
I tapped the main motor with a small screwdriver whilst it was running slow, and it speeded up to normal for a few seconds and then stopped.
The problem was a worn set of brushes, which even under spring pressure were responsible for the erratic motor performance.

I sent the worn brushes to a company who produced copy replacement brushes with identical properties.
I had been tempted to file down some AC mains units, but was warned that low voltage DC brushes need to have a copper content to reduce wear on the commutator of a DC motor!
The replacement brushes arrived after a few days, were fitted, and the problem resolved. My GS was restored to full function.

David

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Terry Sills
Phenomenal Film Handler

Posts: 1423
From: Weymouth,Dorset,England
Registered: Oct 2012

posted March 01, 2018 03:55 PM

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I was tempted to buy a GS1200 many times because of the stunning looks and the technical specifications. Thank goodness I didn't. They are a nightmare of multiple problems. It seems they are just too sophisticated to be reliable. When one problem is resolved another rears it's head. Glad I stuck to mono sound machines.

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted March 01, 2018 05:31 PM

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Thanks Renzo

I can get a 400V 6A ZR-1044 Type 6A4/P600G SSR..diode, would that be the ones Thomas mentions as a replacement?

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Thomas Knappstein
Expert Film Handler

Posts: 124
From: Erwitte, Germany
Registered: Oct 2017

posted March 01, 2018 10:20 PM

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Hi Graham!
I used the BY 500/600 Diodes over 20 Years.

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted March 01, 2018 11:08 PM

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Thanks Thomas [Smile]

[Smile]

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