I am getting faster with every unit. There are some neuralgic points that always fail. On the power supply it is definitely the transistor 7477 which was in almost all units broken or got killed during ling time testing.
On the amplifier part one TDA2030 was not working – only a buzzing noise on its output. To check it I removed first the cable from the pre-amplifier and checked the input signal. When one channel is working it is quite easy to compare the voltages and audio signals. This leads quickly to the conclusion that the TDA2030 was broken. I replaced both to avoid any disharmony between having two different amplifiers.
First, I ordered TDA2030AV but noticed afterwards that they cannot cope with 36V. So be careful when ordering them. However, the voltage in the machine is 38V – always higher than in the service manual and even above the limits of the original amplifier ICs.
Got the CDM2 working by just changing the capacitors. Works like a charm, plays all Cd’s and even jumps between tracks without any issues.
Almost all capacitors got replaced – only a view are backordered since months and I need to wait until I get them all.
Still need to test the tuner part (but it was working before).
I will not be able to repair the tape mechanism without a new fly wheel. My own prints have, of course, horrible wow and flutter values. Need to wait until I get my hands on a donor…