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Old 11th Nov 2021, 12:02 pm   #30
Phantomrose1999
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Join Date: Mar 2008
Location: Melbourne, Victoria, Australia
Posts: 289
Default Re: Grundig TK27 - Low audio output

being fundamentally lazy, i loosened the screws holding the sliding block a little and then super glued them so the screws dont move. Lots of oil and it moves very freely now.

Also lightly sanded every contact, then used contact cleaner and dried them. All switches on both halves of the slider open and close every contact as they should.

Put it back together and had the low volume problem again, AND no bias signal.. lol Whole fiddling with the volume control full volume came back so i replaced three wax caps that did not look healthy, 2x big 0.22uF, (one was suspect when measured) and a 0.033uF all on the main PCB. Put it back together and have full volume. So one down.

The record is still a problem, when pressing the red record button, at one attempt i heard a "clunk" and the bias signal appeared !! see image.

At the next attempt of course it was gone. It did come back a few times, but cant get it back now.

I think the switch with the sliders at the bottom right is fine now, there must be another switch that is part of the record / amp switching.. any suggestions ?
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