What was found
FO RIGHT SIDE OVERHEAT LIGHT ILLUMINATED AFTER ENGINE START. COMPLETED QRH CHECKLIST AND LIGHT ILLUMINATED AGAIN. GROUNDED - YES. PERFORMED RIGHT SIDE WHCU BITE REF FIM 30-41 TASK 801. FOUND FAULT FOR P5-9 CTRL POWER. RIGHT SIDE WHCU REMOVED AND REPLACED REF AMM 30-41-11. NO HELP. REINSTALLED ORIGINAL WHCU FOR RIGHT SIDE WINDOW. REMOVED AND REPLACED WINDOW PITOT HEAT MODULE REF AMM 30-41-41. PERFORMED WHCU TEST FOR RIGHT SIDE WINDOW REF AMM 30-41-11. PERFORMED WINDOW HEAT SYSTEM OPERATIONAL TEST REF AMM 30-41-00-710-801. T/S PER FIM 30-41 TASK 813. ALL TEST PASS. OPS CKS GOOD. NO FAULTS. ETOPS SIGNIFICANT SYSTEM GROUND VERIFICATION SUCCESSFUL.