Technics SL-7 hum on one channel

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Joined: 09 Oct 2011 11:22
Location: Sweden

Technics SL-7 hum on one channel

Post by Micleg » 06 Oct 2019 11:31

Hi! I just hooked my Technics SL-7 up again and this time I get no sound from one of the channels. I have tried different cartridges and also taking it out and inserting it again some times in case there is some dirt in the catridge conectors but still only a quite loud hum from that channel and no sound. Tried switching the working channel's connector on the RIAA unit so I know it works from there on. I also replaced the RCA connector. Still only hum.

I took it apart and measure the cable from the connector inside and the cable is not broken but I am not sure about was resistance I should be able to measure between channels (circuit board and inwards). Should it be infinite? I have re-soldered the connector on the motherboard.

From the mother board connector there isn't much but the cable to the circuit board in the cover (haven't been able to get to that circuit board yet). It is merely connector->cable->circuit board->cable->cartridge.

So I am asking you if you have the answer to these questions two (with no connection to Monty Python at all):

- What could cause the hum? Can't hear any on it on the working channel.

- Can I get to the circuit board with the cables from the cartridge without having tuning problems afterwards? Things not working bacuse they have shifted in place.

Best regards,

Schema for affected parts
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