To be able to locate the defect on the CD-Player I do need some spare parts. Right now the error could be somewhere at the CDM2 mechanics/controller board or at the decoder panel. I do not want to disassemble one of my other two devices for testing purposes, thus I have done some research in which CD-Player from Philips or […]
Month: August 2020
More CD-Player issues
After the amplifier is working it is time to check the CD-Player. Unfortunately it was not all the time working. Sometimes the CD was spinning faster and faster, the controller was unable to read the TOC returned an error. It was working better when the Decoder Panel was in a vertical position. So I thought it might be a loose contact. I […]
Repairing the amplifier – Part2
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 […]
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 […]
Service Manual in German language
I was able to buy some service manuals from a radio repair shop in Austria which, unfortunately, ceased business. There was a little hope that it contains all pages inclusive chapter 9 (modifications). Unfortunately chapter 9 was missing and I really think it was never written. It seems there is no documentation available for the changes, so the PCBs often […]
Workplace update
During analysation of the second unit I noticed that I need a frequency generator to be able to measure the audio channels. Real measurements based on a connected music box will not lead to any success. I came up with a cheap Chinese frequency generator. It delivers accurate results and offers a lot of feature for its price. However, its […]
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 […]