You will have to desolder all the transistors and measure them, also the resistors and diodes. the 2n midelos, checking that they are correctly insulated from the heatsink. at the exit there would have to be a few mV not 47 V, 47-47 equal to 0V, if you place the negative point of the polymer to mass and the positive one to the exit, if negative voltage leads the 2n connected to the negative. if positive voltage leads the 2n connected to the positive. when they both drive approximately 0V. if one of them fails because it gives half + or - 47V. some transistor is wrong or badly insulated from the heatsink. The resting current should be about 200 mA or less, if the current is too small, the output transistors do not drive. and if it is very big you have a short on some transistor. A cordial greeting.