Confirmed/Replaced keyboard assembly and repaired the Nav board to correct the return issues. Updated software to the latest version. Aligned unit for optimum performance. Unit passes all tests and is operating within normal limits. The Main and GPS softwares are at the latest revision. This unit complies with Service Bulletins No. 9906, 9907, 9908, 0003, 0004, 0007, 0009, 0011, 0014, 0016, 0020, 0021, 0105, 0107, 0116, 0201, 0204, 0205, 0216, 0218, 0334, 0308, 0309, 0502, 0515, 0521, 0706, and 0844. This unit complies with MOD 1 per Garmin's Service Bulletin No. 0019. This unit complies with MOD 2 per Garmin's Service Bulletin No. 0101. This unit complies with MOD 3 per Garmin's Service Bulletin No. 02038. This unit complies with MOD 4 per Garmin's Service Bulletin No. 0207. This unit complies with MOD 5 per Garmin's Service Bulletin No. 0211. Work performed in accordance with EASA Part-145 and EASA Part-145 Approval Number: EASA.145.5514. Reference FAA Form 8130-3. Part: GNS430, P/N 011-00280-10, S/N 97129149, Qty 1. Status: REPAIRED. Work Order/RMA: 48048427.