8mm Forum: Sound Problem on ST1200 HD

This is topic Sound Problem on ST1200 HD in forum 8mm Forum at 8mm Forum.

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Posted by Bob Pucci (Member # 8) on July 14, 2004, 06:55 AM:

Can Mr.Elmo or other Elmo gru's answer this werid problem for me.Last time that I used this projector,about three months ago it worked perfectly.When I went to use it all that I got from the sound was a loud hum.So I took the film out and pushed the record button for 30 seconds and trie it.Now it works perfectly.

Any answers.Thanks

Posted by Steve Klare (Member # 12) on July 14, 2004, 07:50 AM:

I'm not a guru, but I've noticed on my ST-800 that sometimes after it's been idle for a while it produces very little audio signal, to the point where the hum is much more audible than the sound. I've found that tapping the record key a few times restores things to normal. This is actually part of the pre-show ritual these days.

(I have a feeling that an oxide is building up which this breaks)

When I first got the projector I had a similar problem that was solved by inserting a plug into the headphone jack and then pulling it out. I'm guessing this one was also oxidation related. It has not recurred since then.

Posted by Kevin Faulkner (Member # 6) on July 15, 2004, 06:19 PM:

Bob, Steves explanation is spot on. Most people use their machines for mainly playback so the record/playback switches remain in one position. An oxide coating tends to build up on the exposed terminals within the switch bank and this results in bad continuity. The switches if used regularly are self cleaning so what you are doing does help to sort the problem.
I put my GS into record several times on each use just to keep the switch contacts clean.

Kev.

Posted by Bob Pucci (Member # 8) on July 15, 2004, 06:30 PM:

Thanks Steve and Kevin.From now on I will do that every time I use one of my machines.I have a GS also.Thanks again.

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