Hello shoji, Testing again IC1 and IC2 I found lower values, I had to set the multimeter in the lowest range position 200m. I noticed about IC2 that pin1 was broken and replaced by a soldered wire. The mainboard seems to have been removed in the past,it is fixed with only one screw and the cover on the cushion of the tonearm's motor is missing.
Now I'm faced
with my soldering inexperience and after your warning caution it would be wise not to remove the capacitor. I should learn and try before first, I think. Although I suppose there is a hierarchy in testing the components is it possible to test rectifier and the input from CN1 and how to measure values?