What was found
CLIMBING THROUGH 20K FT OVHD PANEL LIGHTS AND NUMEROUS OTHER COCKPIT LIGHTS BEGAN TO FLICKER. APPROX 5 SECS LATER ELECTICAL FAILURE OCCURED FOR APPROX 15 SEC, THEN PWR CAME BACK ON. THEN FOR APPROX 3-5 SECS PWR WOULD GO OFF THEN ON. WHEN PWR WENT OFF THE 1ST TIME THE EMER PWR SWITCH WAS TURNED ON AND THE APU WAS PLACED TO START. AFTER 5 SECS PWR CAME ON AND REMAINED ON AND THE FLICKERING STOPPED. A WINDSHIELD OVT LIGHT REMAINED ON THE OAP AND THE AUTO THROTTLES WOULD NOT ENGAGE. BOTH THE CAPTS AND F/OS PFDS AND NDS WENT BLANK. REPLACED BPU AND R2-50, RAN AND LOADED GENS SWAPPED PWR OK.