8mm Forum: Eumig 824 sound not working

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Posted by Luke Coiro (Member # 1380) on November 14, 2012, 07:35 AM:

Not getting any sound with one of my two Eumig 824 projectors. I know it's not the speaker as I swapped over the covers between the two machines and I get sound with the one that works with either cover. Any ideas on what could be the problem?

Posted by Martin Jones (Member # 1163) on November 14, 2012, 09:02 AM:

Only one piece of advice that can be given on this point as you have already exonerated the speaker and its external speaker socket by changing the backs.
You will find the Amplifier Fuse either on the sound panel nearest to the back (in a clip mounting) or on the connection panel of the large transformer (in a plastic tube mount, the end is a bayonet fit cover).
Try a replacement of the next higher milliamp rating; if everything is OK revert to the correct rating. If it still does not work, I would ONLY recommend consulting an EXPERIENCED audio technician as these amplifiers are not only difficult to get at but are also relatively "crude" in their design and construction (although brilliant in their performance when working properly !)and are difficult to work on. Enormous damage can be inflicted by a rouge soldering iron!
I am always filled with trepidation when I have to work on one of my Eumigs, despite having over 45 years of Audio Servicing experience.
Martin

Posted by Luke Coiro (Member # 1380) on November 15, 2012, 03:13 PM:

Well I seemed to have fixed the sound problem. All I did was removed the fuse on the board and it checked ok with a multimeter. Then played around with the record button (pushed it in and out with no film running) and adjusted the two pins on the cover that make contact with the board. Put the cover back on, ran a film and the sound is now there. Thank god it wasn't anything major like the amp failing.

Posted by Pasquale DAlessio (Member # 2052) on November 15, 2012, 06:14 PM:

Well done Luke!

Posted by Janice Glesser (Member # 2758) on November 15, 2012, 08:24 PM:

Glad it was something easy Luke!

Posted by Maurice Leakey (Member # 916) on November 16, 2012, 02:39 AM:

Luke
Do you mean the two spring contacts for the speaker connection?

Posted by Luke Coiro (Member # 1380) on November 16, 2012, 04:02 AM:

Yes the spring contacts. Don't think it was them as the cover worked when I swapped them around with my other machine. I think it had something to do with fiddling around with the record button.

Posted by Paul Adsett (Member # 25) on November 16, 2012, 09:22 AM:

I think the electronics on the Eumigs are extremely reliable, and I have never experienced any electronic problems in 40 years of owning many Eumig projectors. The circuit board design and construction quality is really excellent, with good spacing between components and circuit tracks, and trouble free soldering. Eumigs do not seem to suffer from cracked soldering and delamination of printed circuit boards that sometimes occur on Elmo's.
The 824 problem was almost certainly a dirty or corroded contact on the record button slider switch, which is located on the circuit board and connects to the red button via a wire cable. Just working the switch solved the problem, and a drop of switch cleaner will lubricate and clean the contacts and avoid any futher problems.

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