As the analysis has shown there war somewhere a cold joint which causes the break-down of the power supply for the CD-Player. It took me about 4 hours to identify that resistor 3490 from time to time failed to do its job. Such things causes grey hairs…
The problem with the power supply panel is the heavy transformer. It bends the board when not mounted correctly or when handling the board outside. Thus cold joints are very likely and it happened now several times that a SMD resistor or capacitor on the rear side failed.
I also replaced all the capacitors on the power supply board, switched to 230V (as shown in my videos) and now all the voltages are much closer to the values in the service manual.
However, so far the good news. The bad news are that it seems the CD-Laser of the CDM4/19 is dead. Whilst it worked from time to time on some tracks I noticed the current of the laser dropped quickly. The history of the conducted reparations on the unit is unknown. Maybe someone set the current too high? Could this be my first dead laser? I will do more tests when I find some time.
Unfortunately I do not have any spare parts for a CDM4 and not a single working CDM2 at the moment. Need to search for a donor. Anyway, in the meantime I will try to repair two of my CDM2’s…
Material costs:
Resistor & capacitors around 15€
Time spent 7,5h
I really need to replace this bad job. Usually this is a usable resistor – I have doubt this replacement is usable.
New Nichicon Low ESR, long life capacitors
This little resistor was broken and CD power supply failed. Costs about 10 cent but has a huge impact.
LCD panel got fixed