8mm Forum: Bad noise from my GS1200. What can be the cause?

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Posted by Matthieu van der Sluis (Member # 6040) on November 19, 2019, 03:56 AM:

My Elmo GS1200 is making this noise when I turn the sound On.
https://drive.google.com/file/d/1cdIfr6tnSQX7ui-BhD2f5eWPxxtrPjr5/view?usp=sharing

Maybe it's coïnsidetial, but I think it started after I use Filmguerd in a very wet manor.
Lateron I learned to use only a small amound and dry it afterwards.
Is this possible, or do you recognize this as a defect of another manor?
Or do I need to clean trhe Soundheads really good.
I already tried to use alcohol tissues for this, but that did not help.

Or do I go to van Eck for a repair?

Posted by Steve Klare (Member # 12) on November 19, 2019, 05:05 AM:

It’s always good to start by working all the audio switches and plugging/unplugging the jacks about 10 times each.

Maybe it will fix it, maybe it won’t, but it costs nothing to try it.

(It’s probably not your heads)

Posted by Stuart Hilliker (Member # 737) on November 19, 2019, 06:21 AM:

It’s worth trying the record switch trick. With no film threaded and the projector running, press the rear record enable button and repeatedly press the record switches. This should help to remove any dirt and oxidation from the contacts. It can take a few goes but usually helps.

Posted by Steve Klare (Member # 12) on November 19, 2019, 08:09 AM:

The record key maneuver also works with the machine off and unplugged, and without all the racket through the speakers you won't scare the cat!

Quite often I do it before anything else, just as maintenance.

Posted by Paul Adsett (Member # 25) on November 19, 2019, 09:41 AM:

I've never heard a sound like that before from my own GS1200'S.
It's obviously not a mechanical issue. Sounds almost like feedback in the amplifier. Definitely take Steve's advice and manipulate the switches. Failing that, remove the amplifier module( easy to do- see GS1200 manual on this web site) and clean and spray the mono/stereo and optical/magnetic slide switches with contact cleaner/lubricant. Also clean and spray the interface contacts between the amplifier module and the main control board. All these contacts can give major noise problems if they are not perfectly clean and free of corrosion.

Posted by Maurice Leakey (Member # 916) on November 19, 2019, 10:39 AM:

Probably dry joints somewhere in the amplifier, or dirty switch contacts as mentioned.

Posted by Matthieu van der Sluis (Member # 6040) on November 20, 2019, 07:03 AM:

I'm going to try this all out and let you know if it worked.

Posted by Mathew James (Member # 4581) on November 20, 2019, 08:08 AM:

I agree that this must be a bad switch or contact....

However, it also sounds like you were watching star wars last, and a piece of film of the 'wookie' scene is stuck in the sound path [Smile]

This should be called 'Wookie Warble' [Big Grin]

Hope you can fix it soon!

Wookie Warble!!!

Posted by Steve Klare (Member # 12) on November 20, 2019, 08:33 AM:

I have an Elmo machine that had been forgotten in the box brand new. When I (carefully) powered it up 40-ish years later it broke into an oscillation like this when I turned the volume up.

I guessed it was because the electrolytic capacitors had sat dead so long they weren't formed up anymore. I let it sit powered up for a whole day and every time I walked past it, I had to turn the volume up higher for it to make the sound. By the end of the day it was fine all the way up to full throttle and it still is.

This GS may (or may not) have the equal but opposite problem, the caps have so many hours they are drying out.

-still the same: we hope the switch trick works, no need to rebuild the engine when a new battery would fix it!

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