A well-known disease in this series, Onkyo a, the time for any malfunction of the Input Vorwählers is.
Contact problems often occur due to contamination and corrosion inside the rotary switch, which results in irregular and arbitrary jumping around between the inputs.
However, there are often one or more positions of the rotary switch in which the problem occurs less frequently or no longer at all.
The problem can almost always be eliminated by treating the inner workings of the rotary switch with mechanical cleaning of the contact surfaces.
A recurrence of the problem after a certain time frame cannot be ruled out.
Success largely depends on the intensity of cleaning and the means used.
I bought the amplifier 8850 from Onkyo in January 1992 with CD player DX 6830,Casettendeck TA 2870,tuner T 4830 all from Onkyo and Revox speakers and have not had any failures until today. I am more than satisfied!!!
The error described above can be easily fixed. Simply pull off the input selector switch(input Selector). Then put on a cordless screwdriver with a slot lathe and let it rotate for about 30 seconds with little turning power. The energy cleans the contacts and the selector switch works properly again. No more jumping back and forth!