What was found
AT ROTATION (MAIN WHEEL LIFTOFF), CAPTAIN LOST ALL INSTRUMENTS. THE FOLLOWING LIGHTS ILLUMINATED ON S/O PANEL: GEN 1 OFF, L EMER AC BUS OFF, AC BUS 1 OFF, AC BUS TIE 1 ISOL, L EMER DC BUS OFF, DC BUS 1 OFF. SEVERAL WARNING HORNS GOING OFF THAT COULD NOT BE SILENCED. ON T/O ROLL, ALL ENGINES WERE PRODUCING THRUST, BUT IT TOOK ENGINE NR 1 N2 GAUGE UNTIL 100 KNOTS TO SHOW A PROPER INDICATION, IT WAS CYCLING PRYOR TO THAT. WHILE FLYING BACK TO KIND, GEN NR 1 KEPT COMING ON LINE DROPING OFF. EVENTUALLY IT FIXED ITSELF JUST PRIOR TO LANDING, EVEN PARALLELED THE GENS. HEAVY RAIN CAME THROUGH WHILE A/C SAT ON RAMP. DRIED VISIBLE WATER, FACT 1, NR 2, NR 3 ENG AC GENERATOR ADJ/TEST GOOD PER MM.