What was found
FORWARD LEFT WINDOW OVERHEAT WITH MASTER CAUTION @ FL 330. RAN QRH. LIGHTS CAME BACK ON. GROUNDED - YES. FOUND CIRCUIT BREAKER B9 POPPED. PERFORMED BITE CHECK OF LEFT WINDOW HEAT CONTROL UNIT. BIT VERIFIED P5-9 FAULT. SWAPPED WHCU'S FAULT DID NOT FOLLOW, SWAPPED WHCU'S TO ORIGINAL POSITION, PERFORMED BITE OF BOTH WHCU'S. NO FAULT INDICATED BIT VERIFIED. WINDOW HEAT OPS CHECK NORMAL IAW B737-900 AMM 30-41-00-710-801. AIRCRAFT IS RESTRICTED FROM ETOP SERVICE PER SEA MX CONT. CONTROL. PER SEAMC TOP DEFERRAL HAVE BEEN REMOVED. LEFT HAND WINDOW OVERHEAT PERFORMANCE NORMAL.