What was found
ON TAKEOFF 27K BUMP #1 ENG EGT WENT SOLID RED UNTIL POWER REDUCTION AT 1000 AGL. GROUNDED - YES. CHECKED FOR EGT SYS FAULTS AND FOUND ONE OCCURRENCE OF MSG 77-20861, BOTTOM LEFT EGT OUT OF RANGE. ACCOMPLISHED B737-800 FIM 77-05 TASK 801. NO DEFECTS NOTED. TESTED S3 EGT SEGMENT FOR PROPER RESISTANCE VALUES IAW AMM 77-21-01-200-801, NO DEFECTS. CLEANED EGT SYSTEM CONNECTORS IAW AMM 77-21-00-140-801. ETOPS GROUND VERIFICATION TEST SUCCESSFUL- #1 ENG EEC TEST REF AMM 73-21-00-700-804. EGT PRE CLEANED TEMPS AS FOLLOWS: S1-180, S2-142, S3-242, S4-184. POST CLEANED EGT TEMPS: S1-78, S2-44, S3-43, S4- 87. OBSERVING THAT AFTER CLEANING S-3 CAME DOWN TO WITHIN LIMITS OF OTHER SENSOR VALUES.