Hi Chris,
F76 is displayed when there is an abnormality in the output voltage of the stabilized power supply;this is due to any of the
DC voltages(+9V,+7V,-7V,+5V,+5.3V,etc.);pressing 'STOP' button on the keyboard will bring up the next error on the
display;anyway,surely you know how to find out the bad cap(s).