What was found
WHILE PERFORMING TROUBLESHOOTING AND REPAIR OF 4035-01 SERIES TRANSIENT SUPPRESSION UNITS (TSU) IAW COMPONENT MM 28-44-64, REV 2, DATED 20/04/2007, IT WAS DISCOVERED THAT VARIOUS UNITS (7 TOTAL) SHOWED EVIDENCE OF CONTAMINATION ON INTERIOR SURFACES FROM WHAT APPEARS TO BE MOISTURE INTRUSION THROUGH THE CASE SEALS. AFFECTED UNITS HAVE BEEN PLACED IN QUARANTINE. IMMEDIATELY NOTIFIED THE ORIGINAL EQUIPMENT MFG AND PRODUCTION AUTHORITY HOLDER, OF THE FINDINGS. COORDINATING WITH ENGINEERING AND QUALITY REPRESENTATIVES ON FURTHER ACTION AND FINAL DISPOSITION. AFFECTED UNITS TO REMAIN IN QUARANTINE UNTIL GUIDANCE IS RECEIVED. CONSULTED WITH FSDO, PMI. RECOMMENDED ACTION: SUBMIT SDR IAW 14 CFR PART 145.221 AND REPAIR STATION QUALITY CONTROL MANUAL PROCEDURES. AFFECTED PN 4035-01 AFFECTED SN: 0123, 0408, 1034, 1115, 1313, 1403, 1888. UNITS USED ON AC FUEL QUANTITY INDICATING SYS, INSTALLED IAW STC00847S-28-2.