The motherboard is located in display chassis. Note all of the Fairchild chips, dated from 1973-'74. I have identified the suspect transistor and resistor that are out of spec, but more issues are likely present. I noticed that someone attempted to re-solder a number of connections, perhaps in an effort to repair the unit at some time in the past. Click image for larger view.
A Fairchild SL30342 with a production date of early April 1974.