Yesterday I was able to play about 15 games (and get my highest score ever of 324 Million !) and now there are no switch errors.
Before I turned the game on I reseated the switch matrix row connector (which I had tried before a couple of times back when I was trying to find the cause of these switch errors)
I am now 99% sure all my switch problems are connector related .
Time to order some .100 connectors and replace the switch matrix connectors with Trifurcon which is what I should have done in the 1st place no doubt !