Might be a good idea to also check your power supply voltage at EPROMS on Main Board. Make sure you have 5.2vdc with very low ripple on top right (+) and bottom left (-) pins of a chip. If voltage is set at PS, (.5) volt can be lost in wiring. Ripple can be checked by putting a True RMS meter on AC and checking the 5.2 volts. AC should read close to zero.
