[Patrick]

Disconnect the wire from the socket (where the 4.7k is attached)and see if the voltage goes up. If so your socket has a internal short. If not check for shorted rubber wire going to the pushbuttons.

Terry

Thanks Terry,

I hadn't even considered a shorted socket. I did find a pic online of the 150 ohm resistor on the chassis. It is attached to an inuslated standoff screwed to the pushbuttons. I've circles it in red. 

   

But I cannot find it on the schematic.  The schematic show only two 150 ohm resistors, #34 and #60, which I can account for. 

Pat