I just picked up a BC9300 for 15 GBP, advertised as defect but with a relay clicking. True enough - I just connected it to mains, and I hear a click from a relay. Other than that, there is no stand-by light. I have opened the unit (the glass panel was of course loose, so I took that off), and I see no obvious signs. Is there a known problem, like e.g. cracked solder joints around a certain capacitor that I should look for, or should I start by seeing if I have the correct voltages as per the service manual?