What was found
AFTER PUSH BACK, LEFT GENERATOR WOULD NOT COME ONLINE CAPTAINS PFD NAV DISPLAY AND PRIMARY ENGINE INSTRUMENTS DISPLAY WENT BLANK AND REMAINED BLANK UNTIL ENGINE SHUTDOOWN AT GATE AND ON APU POWER. F/O'S PFD HAD DISPLAY SOURCE DISPLAYED WHEN 3 DU'S WERE BLANK. ACFT GROUNDED. PERFORMED ENGINE RUN WITH CREW. FOUND LT ENGINE GENERATOR WILL NOT GO ONLINE. RT ENGINE GENERATOR POWER A/C WITH NO DEFECTS NOTED. LT IDG OIL LEVEL FULL. R & R NR 1 ENGINE GCB IAW MM 24-21-41. OPS CHECKED GOOD.