Hi all,
I'm battling away with the two 7904s. The one with the faulty CRT had a functional power supply. The other one was completely dead despite having intact fuses. I transplanted the working power supply into the dead one and it tried to start but began ticking. I measured the resistances of the power rails as described in the handbook and if anything they are a bit higher than specified i.e no shorts. Progressively unplugging the various connections as described in the troubleshooting guide does not isolate any faulty board, i.e. it still ticks. My question is, is it normal for a 7904 power supply to tick if run disconnected with no load or is it a sign that the power supply has developed a fault?
Morris
