Well, the preamplifier is working and not to continue with the TDA2030. Since the channels are separated but both do not have a signal it was quite clear it can only be a control of both channels which is not working. Luckily there is only one circuit that can cause the troubles. The circuit around 7310-7314 mutes the signal for […]
Category: Unit 2
Repairing the amplifier – Part 1
After I have repaired the power supply of the second unit and check all of the provided voltages it was time to continue with the amplifier. Since there is no sound on both channels it must have something to do with either the supply or controls. In a first step I checked the voltages and noticed F with +38V was […]
Power Supply Issues
A first measurement of the voltages has shown that +9V and +5V are missing because of a broken fuse (1467). After ordering some spare parts – basically trying to get every component of the PCB – I replaced the fuse 1467 and also removed the transistors 7477 and 7478 of the same supply line. Testing has shown that they are […]
Evaluation of Unit #2
Whilst one sound machine is working – more or less, not perfect but I will take care about later – I have done an analysation of the second unit and the issues. First, when switching on the device the power LED is not working. The background LCD is working and the cassette part shows all options. There is no reaction […]