I have a Naim Nait series 5, perhaps first series, the transistors mounted are all from the ZTX series excluding the power amplifiers which are BD. I found a ZTX652 and a ZTX214 faulty and some resistors. After replacing the faulty components the amplifier now works, it does not absorb and there is a signal. I would like to be sure of the repair and I am looking for the diagram or some information on the bias etc.