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Author Topic: GS1200 Take up Reel problems....
Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 22, 2005 08:45 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
Ok. It was bound to happen. My GS needs some tinkering. I noticed when rerecording Toy Story Audio the Take up reel which was doing fine the first 400ft (Toy story mounted on 2x800ft reels) started to move very slowly after that. By the time it got to the end of the 800fter it was almost not moving. I could easily stop it with one finger. Does anyone know how to adjust the torque on the take up motor or should I be looking in another direction?

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 23, 2005 01:47 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
Look near the front arm motor. There is a little board with three trimmers. It's the first or the second. If this way doesn't fix the problem, I have a bad news for you. The problem comes from the big relay on the main board. It's necessary to change it. I can explain how to do it (there is a topic in this forum on this argument), or I can do it for you...(you pay only the shipping cost and the spare parts) [Wink]
Of course you have to disassemble the main board from the GS (it's easy...) to send it separatly.

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Bye
Ugo

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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 23, 2005 07:11 AM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
Hi Ugo,
Thanks for the reply! Can you post some pictures of the switches on the motor? I couldn't find them. Also thanks for the offer. Lets hope that it doesn't get to that!

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 23, 2005 10:59 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
If you don't see the little board with three trimmers, it means you have a ver. I.
The service manual says: If insufficient torque, change the position of wire from the 3v to the terminal 4v on the transformer. Look the transformer: there two sockets with the number 3 and 4. If the 3 is connected, the 4 is free. If the 4 is connected.. you have the problem on the main board.

[ September 23, 2005, 01:25 PM: Message edited by: Ugo Grassi ]

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Bye
Ugo

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Mark Norton
Master Film Handler

Posts: 330
From: Hampton Hill, Middlesex, U.K.
Registered: Feb 2004

- posted September 23, 2005 02:55 PM      Profile for Mark Norton   Author's Homepage     Send New Private Message       Edit/Delete Post 
I've had this same problem on my GS1200 and it was the relays on the take up/rewind curcuit that needed changing. Could it be a common problem due to age?

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John Cook
Expert Film Handler

Posts: 183
From: Papillion, NE
Registered: Apr 2004

- posted September 23, 2005 05:45 PM      Profile for John Cook   Author's Homepage   Email John Cook   Send New Private Message       Edit/Delete Post 
A relay problem? Has anyone disassembled their relay after removal, if this is in fact the problem the relay contact surfaces must be pitting and or covered with carbon from arcing during open/closure.

Since his motor was turning although slowly we do know that the solenoid was working only the contacts were presenting a higher resistance to current flow.

I wonder if they can be disassembled and cleaned, or worst case buffed?

Regards, John

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 23, 2005 05:52 PM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
I did it, but it's hard to clean the contacts, and the result isn't reliable. I cleaned the contact on the GS I sold to Jean Marc (and that machine had few working hours behind) and when the GS arrived to France... the take up reels fineshed to work!!
I sent to Jean Marc a whole new main board, and when I get back that one defective I changed the relays.

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Bye
Ugo

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John Cook
Expert Film Handler

Posts: 183
From: Papillion, NE
Registered: Apr 2004

- posted September 23, 2005 05:59 PM      Profile for John Cook   Author's Homepage   Email John Cook   Send New Private Message       Edit/Delete Post 
Ugo,

Are the relays in a removable socket(bend back a wire retainer clasp and pull the relay out of the socket) or did you have to suck the solder from the printed circuit board's (PCB) pads in order to remove the relay from the board?

I have to admit I haven't had my GS1200 open yet for any problems, running on borrowed time.

John

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Come visit The Pit
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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 23, 2005 08:51 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
I adjusted the take up reel trim adjustment and it worked a little bit better but I can still stop the reel from turning with my hand. It must be something else. Ok Ugo...how should I go about doing the relay? I have to say I saw the pictures from an earlier post and I was scared...!!!

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 24, 2005 03:17 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
quote:
but I can still stop the reel from turning with my hand.
This is not a test. Is your GS able now to take up the whole 800ft spool?

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Bye
Ugo

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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 24, 2005 08:10 AM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
Yes, there is not much torque but it can take a full 1200ft spool without stopping. Am I crazy? Are all GS's this way? I dont remember ever having a problem with my other ones...

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 24, 2005 09:48 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
Oh no! you are not a crazy. I can never say so! Not I! [Big Grin]

Are you able to measure the voltage supply to the motor? Follow the blue and read cable from the motor to the little board, and measure there the vultage. Let me know..

[ September 25, 2005, 05:10 PM: Message edited by: Ugo Grassi ]

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Ugo

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Mark Norton
Master Film Handler

Posts: 330
From: Hampton Hill, Middlesex, U.K.
Registered: Feb 2004

- posted September 25, 2005 05:47 AM      Profile for Mark Norton   Author's Homepage     Send New Private Message       Edit/Delete Post 
As I remember you can test the supply voltage at either motor as they are both on the same curcuit. The supply voltage in FWD should be near 3 volts D.C. and it should be the same in reverse projection. If you have the full 3 volts in reverse projection (Not rewind of course) but a voltage drop in FWD projection, (at 1.5 volts the take up reel barley turns), accross the two motors then this would be the same problem I had.
Now I had a well known Elmo specialist replace the relays in mine.

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

- posted September 25, 2005 09:07 AM      Profile for Kevin Faulkner         Edit/Delete Post 
The relays will cause the motors to work, not work or be intermittant. In forwards projection the voltage accross the two motors is in the order of 5.5V (top pot). In reverse projection its about 6V (middle pot) and if the little switch/roller at the film input is activated the voltage should drop to about 5V (bottom pot), if the machine has this facility built in. These voltages are a good setup guide. Voltages are recorded without a load on the motors.
The voltages in the service manual are only good for the ver 1 machines with out the control board next the the rewind motor. With these early machines the voltages were controlled by using differennt tappings on the main transformer. When Elmo introduced the control board they also changed the voltage spec of the motors which means that the 2 versions of motor shouldnt really be swapped otherwsie the torque wont be correct.
Using the above voltages is the way I normally set these machines up. If this doesnt give enough torque then its quite possible that the problem is due to worn brushes or very dirty armatures within the motors. These motors can be stripped down very easily and given a good clean. Its important to make sure that there are no carbon deposits between the armature contact segments.

Kev.

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GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Colin Preston
Film Handler

Posts: 77
From: Northwich, Cheshire, United Kingdom
Registered: Jun 2003

- posted September 25, 2005 04:47 PM      Profile for Colin Preston   Author's Homepage     Send New Private Message       Edit/Delete Post 
I think that Kev is spot on there. I don't know if you chaps recall, but I had the same problem with my GS. Afetr trying lots of things, I ended up having the motor replaced and it has been fine since [Smile] [Smile] (Touch wood)
Col

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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 26, 2005 11:10 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
Ok. I took out the trusty multimeter and it read as follows. The top setting turned out to be 3.75 volts and the middle one read 7 volts! By trying to adjust the top pot I could only make it go lower to 3 volts..but I could never get it to 5.5. So....now what? Do I have to take the motor apart? Sigh...

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 27, 2005 02:00 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
The carbon on the main relay is the caused by the spark product by the electricity when it starts to cross the contacts.
This carbon can interrupt the crossing of electricity, but can also to make a resistance.
If you are sure to the take up reel motor only 3/4 volt arrive, it means the motor is ok and there is a good chance the problem is on the main relays.
If you want I can fix your problem. To disassemble the main board is easy (ask to Jean - Marc..).
Send me a mail if you like...

[ September 27, 2005, 04:57 AM: Message edited by: Ugo Grassi ]

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Ugo

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

- posted September 27, 2005 11:10 AM      Profile for Kevin Faulkner         Edit/Delete Post 
Alan, Does the board have the 2 or 3 pots?

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted September 27, 2005 11:17 AM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
3 pots.

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted September 27, 2005 04:52 PM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
John, excuse I didn't see your question.
The original relays are soldered on the board. [Frown]

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Ugo

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John Cook
Expert Film Handler

Posts: 183
From: Papillion, NE
Registered: Apr 2004

- posted September 27, 2005 06:22 PM      Profile for John Cook   Author's Homepage   Email John Cook   Send New Private Message       Edit/Delete Post 
Ugo,

Thank you for the response. I thought that soldered might be the case considering the fact that people are sending the boards back and forth for repair.

John

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Come visit The Pit
http://members.cox.net/home-theater

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Antoine Orsero
Master Film Handler

Posts: 374
From: marseille france
Registered: Jun 2003

- posted September 28, 2005 12:49 PM      Profile for Antoine Orsero   Author's Homepage     Send New Private Message       Edit/Delete Post 
Good evening,
My problem with my GS1200 is the reverse gear but not rewinding! The reverse gear maet one moment before starting itself! But if I press laterally and slightly on the relay, it start yourself immediately! I looked at the weldings of the relay and they appear good to me! I do not manage to know the origin of this breakdown!

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Tony

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Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

- posted September 29, 2005 03:39 AM      Profile for Jean-Marc Toussaint   Author's Homepage   Email Jean-Marc Toussaint   Send New Private Message       Edit/Delete Post 
Antoine, did you check the little cogs on the rewind motor? A cracked or clogged teeth could be the cause...

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The Grindcave Cinema Website

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