8mm Forum: GS1200 take-up reel stopped working

This is topic GS1200 take-up reel stopped working in forum 8mm Forum at 8mm Forum.

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Posted by Xander van der Merwe (Member # 125) on November 19, 2007, 03:38 AM:

Hi, I need some assistance to trouble shoot and repair my GS1200 take-up reel that suddenly stopped working (doesn't turn at all). I've checked the belt and that is fine. I've unsoldered one of the take-up motor wires and measured the voltage coming from the circuit board as being 0.8V to 0.9V - this seems to be a bit odd? I don't have a 4V generator to test the motor.

Any help/assistance appreciated. I've got a copy of the GS1200 service manual.

Thanks in advance

Update
I found the following link that could explain one probable cause:
http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=001511

Posted by Kevin Faulkner (Member # 6) on November 19, 2007, 04:34 AM:

Does the rewind motor work OK in reverse play? If it does then like the other link you found its probably going to be a transitor or it could be a dirty relay. Try stoping and starting the machine a few times to see if that gets the motor running again.

Kev.

Posted by Paul Adsett (Member # 25) on November 19, 2007, 08:41 AM:

I had this problem on my version 1 GS1200 and I had to replace the forward relay on the main circuit board. That totally solved the problem.

Posted by Xander van der Merwe (Member # 125) on November 20, 2007, 02:05 AM:

Thanks guys. I tried reverse play and the rewind motor (that is the front motor?) works correctly. I tried stopping and starting the machine a few times, but to no avail.

Where would a possible dirty relay be located?

I know a guy that fixes all sorts of electronic gear - I may have to take the machine and service manual to him. I could trouble shoot faulty transistors using a multi-meter many, many years ago, but I think I may have lost that skill now [Smile]

Posted by Paul Adsett (Member # 25) on November 20, 2007, 06:37 PM:

Xander,
The relay that I had to replace on my GS1200 is located on the main board running along the bottom of the machine. If you look at the top(component) side of this board, you will see two large relays, with clear plastic covers, located just behind the flywheel and fan. The one which controls the take up motor is the larger of the two, the forward relay - the one closest to the flywheel. It is a MATSUSHITA NC4-P-DC12V. It is a bear to replace, as you have to remove a lot of harware and all the other circuit boards and harnesses to get the main board out. Then unsoldering the old relay is risky as you can easily damage the circuit boards 30 year old solder runs if you are not extremely careful. Once you have the old relay out, soldering the new relay in is a snap. I was very lucky and managed to successfully replace the relay on my machine, but I thought at one point that I had ruined the solder runs on the board. It is not a job for the faint of heart!
Since I replaced the relay, I have had no more motor or function control problems in my GS.

Posted by Kevin Faulkner (Member # 6) on November 21, 2007, 03:51 AM:

I had this very same problem on my own GS Xenon. What I did was to remove the relay from the board and then open it up and clean the contacts. I did this by using very thin card drowned in switch cleaner and then carefully pushed it in and out between all of the contacts. The switch cleaner is also a lube and since doing this I have had no more trouble at all.

The relays are still available direct from Panasonic Relay division. You will have to look them up in your own country and there could be a lead time of up to 16 weeks.

Try cleaning first.

Kev.

Posted by Tony Milman (Member # 7) on November 21, 2007, 04:28 PM:

Kevin,
Do you have to remove the relay completely to do this? Is there any device that like a socket could sit on the board for the relay to sit in to save another soldering -desoldering in the future?

Posted by Kevin Faulkner (Member # 6) on November 21, 2007, 04:48 PM:

Tony, Yes Panasonic do do a range of bases that allow you to plug the relays in and out at will. From reading the spec's I think the down side of using sockets is that the current capability is slightly reduced. This might be the reason why Elmo soldered them direct.
I found there just wasnt the room to work on these relays in situ which is the reason for removing them. I couldn't even get the covers off them while they were in place.

You can unsolder these relays from underneath the machine without having to remove the bottom circuit board from the machine so it's a fairly easy job.

Providing a desolder pump is used the relays come out easily and nice and clean.
The plastic cover can then be removed and the contacts cleaned. I did check each of the contacts on mine using a magnifier glass and I didn't spot any pitting or burning on the contacts. Cleaning the contacts as described above has kept the problem away for about the last year. [Smile]

Kev.

Posted by Antoine Orsero (Member # 41) on November 22, 2007, 04:18 PM:

I have the same problem on the take-up reel and the reverse play! It is necessary to make heat the projector during 3 minutes so that it works! I cleaned the two relays with the scouring product special contact and everything works well during 10 days and after the problem starts again!

Posted by Ugo Grassi (Member # 139) on November 22, 2007, 06:42 PM:

That's my solution: the advantage is you can mount every 12 v. relay you find in your electronic store. The relays I mounted in these two machines were able to tolerate an higher Amper line. No more contacts problems for the next 50 years!
photo 1
photo 2

Posted by Kevin Faulkner (Member # 6) on November 23, 2007, 01:23 AM:

A very neat job Ugo.

Kev.

Posted by Alex Fox (Member # 94) on November 24, 2007, 10:38 AM:

Hello Kevin,I have tried to locate the relays as you have suggested but I can not match up the number NC4-P-DC12V with anything on the Panasonic list, was there an other number for this relay.Thanks Alex.

Posted by Paul Adsett (Member # 25) on November 24, 2007, 11:36 AM:

Alex,
Here are all the numbers on my GS1200 forward relay:

MATSUSHITA
NC4-P-DC12V
AW4441 806
5A250V AC

Posted by Alex Fox (Member # 94) on November 25, 2007, 09:39 AM:

Hello Paul, Thank you for the the information,I tried with these new numbers but with no success, however I have requsted a search so I will hve to wait and see what the company comes up with.Will let you know the the results I receive . Alex

Posted by Paul Adsett (Member # 25) on November 25, 2007, 09:57 AM:

Alex,
You can get this part from Leon Norris in (appropriately!)Norristown Pennsylvania. That's where I got mine. Give him a call at (610)-275-1225. Leon is 'Mr. Elmo' on this side of the pond, you will find him very helpful, plus he carries a lot of Elmo spare parts.

Posted by Alex Fox (Member # 94) on November 25, 2007, 10:09 AM:

Paul, Thank you once again , will give the gentleman a call. Alex

Posted by Xander van der Merwe (Member # 125) on January 11, 2008, 12:09 AM:

Well, after 8mm withdrawal symptoms got the better of me, I finally took my GS1200 into our local expert -- Kevin Bragg -- who will now fix it for me. On first looks he thought that it was indeed the relay(s) causing my problem. I'll keep you posted as to what he finds.

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