Hi Paul;
After you dis-connect the wire for pins 20 and pins 70, check to see if they work right, If they do then the problem is not in the front end of the circuit. Then take out the memory board, put he wire back in and see if you can toggle them High and Low, if you can't the it is the Motherboard. if it works then most likely it is the Memory board
and that is for another session. Please let me know what you find !!!
Thanks Marty