If you remove the bottom cover you will find there is a solder terminal where the spider thin strands of wire from the cartridge/arm connect to the output cable. They are very fragile! There is neutral and hot just like at the cartridge pins for each channel plus a separate ground. I recall then being color-coded like the cartridge but I'm not certain.You may have a partial short to ground on the bad channel so resoldering those leads might help. In any case, further help is available fron DDarch at Vinyl Nirvana or The Analog Dept