Couldn't tell anything(on you-tube) except it was loud. Try turning off the left channel and with less volume. It could be the Volume pot or the balance pot. I would try a shot of DeOxit and judicious exercise of the pot 1st and flushing out with CRC QD Electronics cleaner to flush out the junk. Then a shot of Faderlube or CRC 626 electronics lube. VERY VERY SHORT SHOTS of DeOxit and Faderlube. Exercise the pot while flushing with CRC. If that doesn't cure it, THEN go ahead and tear it down. Use the least invasive procedure 1st and then graduate up to the more invasive procedures. Also add your location to your profile please.