Beogram 4500 Record player

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mr_anders_son Posted: Sat, Dec 29 2018 2:20 PM

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I have a Beogram 4500. And I can only get sound in one channel. I have check the plug!

Anyone can get me some tips??

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hafenkapitaen replied on Sat, Dec 29 2018 3:32 PM

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Beogram Phono or CD?

If it is a Phono: check the mmc system. at my BG7000 ihe left channel was out. After send replacing the mmc it works fine :-)

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Menahem Yachad replied on Sat, Dec 29 2018 5:43 PM

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So, you have the BeoGram 4500 Turntable, and your MMC is confirmed working on another turntable.

YOUR BG4500 has the RIAA PCB inside, which may have a defective component, or the mute switch adjacent to the RIAA PCB may be defective.

Those are the 2 places to check.

If you have an oscilloscope, you can trace the problem in less than 5 minutes.

Menahem

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Dillen replied on Sat, Dec 29 2018 6:07 PM

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If you are sure, that the problem is not a broken lead inside the DIN plug (that's quite common) or the cartridge (sadly also seen to often),
you could focus on the thin leads from the tonearm. They tend to break where they go from the back end of the tonearm into the carriage housing.

I have seen this many times.
Fiddly - but not impossible to repair, if that's the issue here.
You will have to do continuity tests - or look inside - to confirm.

In decks without RIAA the muting switch grounds the signals from the pickup cartridge.
In decks with RIAA; the muting switch grounds the outputs from the RIAA.
In other words, the muting switch does not break the signal paths. It merely grounds them. So a failing contact point in the muting switch would allow a constant signal through, it would not cause constant silence.

Do be careful if you take off the black carriage cover. The thin leads often stick to the underside of the cover!

Martin