What was found
AT 1000 FT AGL BOTH ENG GENERATORS WERE PROVIDING INTERMIT POWER. BOTH SIDES PFD AND ND WERE FLASHING ON AND OFF WITH THE PWR CYLING. THIS WAS HAPPENING EVERY 1-2 SECS. CAPTS SIDE SWITCHED TO STBY PWR TO REGAIN INST. THE F/O SIDE CONTINUED TO FLICKER AFTER 30 SECS WHEN THE APU WAS UP AND RUNNING PLACED THE F/O SIDE ON APU GEN AFTER TRIPPING THE RT GEN MANUALLY. AFTER THAT WE DID THE CAPTS SIDE AND IT ALL WORKED FINE. WE HAD NO AC CROSS-TIE LOCK OUT DID NOT NOTICE FREQS OR VOLTS AT THE TIME.REPLACED RT GENERATOR AND CSD PER AMM OPS CKS OK.