What was found
"LH ENG BLEED OFF LIGHT. AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE REMOVED + REPLACED LH PRSOV PER AMM 36-11-09 AFTER ENG START NO BLEED LH ENG STATUS MSG + 0 DUCT PRESS C/W HPSOV THUM TEST REF AMM 36-11-07 AND PRV THUMB TEST REF AMM 36-11-18 NO DEFECTS NOTED ON BOTH LH ENG VALVE (HPSOV + PRV) PERFORMED ENG RUN AT IDLE POWER STILL NO BLEED AVAILABLE SWAPPED AIR SUPPLY CAR LH WITH RH (LH M859 P/N 285T1115-15 S/N D00660) (R/H P/N 285T1115-15 S/N D01862) ENG RUN UP SUCCESSFUL PLACED AIR SUPPLY PLACED AIR SUPPLY CARDS BACK TO ORIGINAL CONFIGURATION REMOVED AND REPLACED LH AIR SUPPLY CONTROL CARD PER AMM 36-12-00 OPS CHECK GOOD LH ENG BLEED PRESSURE OK CONTROL CARDS READ AS FOLLOW LH P/N 285T1115-15 S/N D01340 R/H P/N 285T115-15 S/N D01862 A/C OK FOR SERVICING A/C REMAINS NO ETOPS PRSOV OPS AND LEAK CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.