8mm Forum: GS1200 Nervous Breakdown

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Posted by Paul Adsett (Member # 25) on February 12, 2019, 06:19 PM:

Last night I decided to run my version 1 GS1200, which has been idle for several months. Everything ran fine for about 3 minutes, when I heard a strange knocking noise inside the machine. I removed the back cover and located the noise source as originating from the solenoid which lifts the rubber roller off the flywheel, It was pulsing madly up and down, and when I put a little pressure on it the frequency of the vibration increased rapidly, almost like going into resonance. It was like the solenoid was getting an AC voltage applied to it. Anyway I decided to flip the control switches a few times to see if a bad contact was causing the problem, when suddenly the projector went crazy, with the still frame shutter going madly in and out, the projector running very slowly, no reverse, you name it! [Eek!]

I shut everything down, pulled and replaced some of the connectors on the control board, powered back up and everything is operating normally. No idea what happened, but it is a perfect illustration of how touchy and sensitive these overly complex machines are.
The engineer's design philosophy - "simpler is better".

Posted by Kevin Clark (Member # 211) on February 12, 2019, 06:39 PM:

Paul I sympathise greatly with you the GS1200 (all versions) certainly has its moments of madness and hopefully yours will calm down or the fault can be sorted soon. My two are both behaving well at the moment, in fact amazingly well considering a fairly long gap of recent non use.

Around the same time they were first sold I used to repair Japanese designed photocopiers (Minolta & Panasonic) which had similar challenges to overcome with often too many 'whistles and bells' added resulting in strange and 'hope that fixed it' moments even when following every known modification and service guidelines to the T.

If only NASA had made Super 8 projectors (maybe they did?) with military grade fail proof electronics.

Kevin

[ February 15, 2019, 05:55 AM: Message edited by: Kevin Clark ]

Posted by Paul Adsett (Member # 25) on February 12, 2019, 10:26 PM:

Yes Kevin, a super 8 projector built to the requirements of MIL-E-5400. They would all be running like new today and for the next 50 years! [Smile]

Posted by Thomas Knappstein (Member # 6134) on February 12, 2019, 10:27 PM:

Hello Paul!

There is a black sqare Rectifier on the Main Board on the right Side of the Fan Housing. There must be 12-13V DC on it. If not check the Fuse on the Main Transformer.

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