Posted: Sat Dec 14, 2019 11:49pm
I had a Yacht boy from the 70s which I replaced with a Sony 7600 in the early 90s, I still have have it now, had a lot of Cap changes but it is still going strong.
I think the same thing applies, check for corrosion of the tracks on the PCB and and areas where there might be current
flow between tracks due to corrosive effects. The number one problem are the electrolytics, due to them drying out or leaking electrolyte. Make a list of them and change them all, Yes ALL. clean the pcb where they were removed with medical alcohol before replacing them. Special attention to polarities of the capacitors. Clean the waveband switches with proper contact cleaner.
These little Grundigs were quite useful little sets.
To be really smart apply a low voltage in the correct polarity (say 3V) to the new electrolytics to form them. Make sure you discharge them (Short them ) before fitting them to the radio.
Good luck, let me know how it goes. and if you need any more specific help.