Are you sure that the problem is not with the cartridge ? Sadly, it's quite common to see the needle cantilever suspension give up the ghost and often the symptoms are that the cartridge is riding a little high on the record grooves with the cantilever in an odd angle, producing distortion and often jumping tracks. Give it a gentle finger-dab on top of the cartridge and it will fall down to normal position and play fine.
This applies to the original cartridges, presumably because of age. If this is what you experience, you need a new cartridge.
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Martin