What was found
AFTER TAKEOFF, LEFT SIDE "PACK" LIGHT ILLUMINATED. QRH PROCEDURE ACCOMPLISHED AND LIGHT STAYED ON AFTER PUSHING RESET SWITCH. NO OTHER LIGHTS ON WHEN RUNNING QRH. UPON RECALL, AT TOP OF DESCENT, THE LIGHT WENT OUT DURING RESET. SUBSEQUENT, RECALL, ILLUMINATED LT PACK LIGHT AND IT GOES OUT WHEN, PUSH TO RESET, IS PUSHED. ACFT GROUNDED. BITE SHOWS TCV FAULT ON NR 1 CONTROLLER. NO PREVIOUS HISTORY. FAULT RESETS AND BITE TEST NORMAL AMM 21-61-20-400.