Note that all items we supply are engineering spare parts and are supplied to you ONLY on the basis that you have the knowledge and means to fit them without harming yourself or others, or damaging the goods. We do not refund or exchange pcb’s. Because they form part of a larger circuit that may well have other faults and dangerous voltages. If you aren’t capable or qualified to work on amplifiers then please leave it to someone who is. Failure to do this could result in electric shock injury and death. We will not be held responsible for buyers knowledge or lack of it.