400 SERIES MAINTENANCE MANUAL

1 GNS 430 ShownGARMIN International, E. 151st StreetOlathe, KS 66062 USA190-00140-05, Revision COctober 2002400 SERIESMAINTENANCE MANUAL (GNS 430, GNC 420, GPS 400)Page A400 SERIES MAINTENANCE MANUALRev. C P/N 190-00140-05 Copyright 1999-2002 GARMIN Ltd. or its subsidiariesAll Rights ReservedGARMIN International, East 151st Street, Olathe, Kansas 66062, (Europe) 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 9AQ, CorporationNo. 68, Jangshu 2nd Road, Shijr, Taipei County, TaiwanExcept as expressly provided herein, no part of this MANUAL may be reproduced, copied, transmitted,disseminated, downloaded or stored in any storage medium, for any purpose without the express priorwritten consent of GARMIN. GARMIN hereby grants permission to download a single copy of thismanual and of any revision to this MANUAL onto a hard drive or other electronic storage medium to beviewed and to print one copy of this MANUAL or of any revision hereto, provided that such electronic orprinted copy of this MANUAL or revision must contain the complete text of this copyright notice andprovided further that any unauthorized commercial distribution of this MANUAL or any revision hereto isstrictly in this document is subject to change without notice.

2 GARMIN reserves the right to change orimprove its products and to make changes in the content without obligation to notify any person ororganization of such changes or International, E. 151st StreetOlathe, KS 66062 USAT elephone: 913-397-8200 Aviation Panel-Mount Technical Support Line (Toll Free): OF REVISIONSREVISIONREVISIONDATED escriptionECO #Insertion DateByA07/06/99 Initial Release-----B01/26/01 Redraw15007C10/22/02 Redraw19319 GNC and GNS are trademarks of GARMIN Ltd. or its subsidiaries and may not be used without the express permission of SERIES MAINTENANCE MANUAL Page iP/N 190-00140-05 Rev. CLIST OF EFFECTIVE PAGESPageRevisionPageRevisionPageRevisio nPageRevisionAC4-8C5-54 BLANKF7-24 BLANKiC5-1C6-1CA-1 CiiC5-2C6-2CA-2 CiiiC5-3C6-3CB-1 CivC5-4C6-4CB-2 CvC5-5C6-5CB-3 CviC5-6C6-6CB-4 CviiC5-7C6-7CB-5 CviiiC5-8C6-8CB-6 CixC5-9C6-9CB-7 CxC5-10C6-10CB-8 CxiC5-11C6-11CB-9 CxiiC5-12C6-12CB-10C1-1C5-13C6-13CB-11C1 -2C5-14C6-14CB-12C1-3C5-15C6-15CB-13C1-4 C5-16C6-16CB-14C1-5C5-17C6-17CB-15C1-6C5 -18C6-18CB-16C2-1C5-19C6-19CB-17C2-2 BLANK5-20C6-20CB-18CF2-3C5-21C6-21CF2-4 BLANK5-22C6-22CF2-5C5-23C6-23CF2-6 BLANK5-24C6-24CF2-7C5-25C6-25CF2-8 BLANK5-26C6-26CF2-9C5-27C6-27CF2-10 BLANK5-28C6-28C3-1C5-29C6-29C3-2C5-30C6- 30C3-3C5-31C7-1C3-4C5-32C7-2C3-5C5-33CF7 -3C3-6C5-34CF7-4 BLANK3-7C5-35CF7-5C3-8C5-36CF7-6 BLANK3-9C5-37CF7-7C3-10C5-38CF7-8

3 BLANK3-11C5-39CF7-9C3-12C5-40CF7-10 BLANK3-13C5-41CF7-11C3-14C5-42CF7-12 BLANK3-15C5-43CF7-13C3-16 BLANK5-44CF7-14 BLANKF3-17C5-45CF7-15CF3-18 BLANK5-46CF7-16 BLANK4-1C5-47CF7-17C4-2C5-48CF7-18 BLANK4-3C5-49CF7-19C4-4C5-50CF7-20 BLANK4-5C5-51CF7-21C4-6C5-52CF7-22 BLANK4-7C5-53CF7-23C(F) INDICATES FOLDOUT PAGES-PRINT ONE SIDE ONLYPage ii 400 SERIES MAINTENANCE MANUALP/N 190-00140-05 Rev. CThe following are General Safety Precautions that are not related to any specific procedure andtherefore do not appear elsewhere in this MAINTENANCE MANUAL . These are recommendedprecautions that personnel should understand and apply during the many phases of maintenanceand AWAY FROM LIVE CIRCUITS. MAINTENANCE personnel shall observe all safetyregulations at all times.

4 Do not replace components inside the equipment when potentially lethalvoltages are present. Turn off system power before making or breaking electrical any exposed connector, terminal board, or circuit board as a possible shock which retain a charge shall be discharged only when such grounding does not resultin equipment damage. If a test connection to energized equipment is required, make the testequipment ground connection before probing the voltage or signal to be NOT SERVICE ALONE. Personnel shall not under any circumstances reach into or enterany enclosure for the purpose of servicing or adjusting the equipment without immediatepresence or assistance of another person capable of rendering SUBJECT TO EXPORT CONTROL LAWSThis document may contain information which is subject to the Export AdministrationRegulations ( EAR ) issued by the United States Department of Commerce (15 CFR, ChapterVII, Subchapter C) and which may not be exported, released, or disclosed to foreign nationalsinside or outside of the United States without first obtaining an export license.

5 A violation of theEAR may be subject to a penalty of up to 10 years imprisonment and a fine of up toUS $1,000,000 under Section 2410 of the Export Administration Act of 1979. Include this noticewith any reproduced portion of this SERIES HARDWARE MOD LEVEL HISTORYThe following table identifies hardware modification (Mod) Levels for the 400 Levels are listed with the associated service bulletin number, service bulletin date, and thepurpose of the modification. The table is current at the time of publication of this MANUAL (seedate on front cover) and is subject to change without notice. Authorized GARMIN Sales andService Centers are encouraged to access the most up-to-date bulletin and advisory informationon the GARMIN Dealer Resource web site at using their GARMIN-provideduser name and DatePurpose of Modification1SB0019 Nov 7, 200014/28V only, Comm Transmitter Fuse2SB0101 Feb 16, 200114/28V only, Remote COM Transfer3SB0203 Feb 1, 2002430/420; 14/28V only (-10 and 30), Receiver AudioCompressor (recommended only if problem exists)4SB0207 Apr 2, 2002430/420; Remove excessive solder from Comm Board vias400 SERIES MAINTENANCE MANUAL Page iiiP/N 190-00140-05 Rev.

6 CTABLE OF CONTENTSSECTION 1 DESCRIPTION AND INTRODUCTION .. Covered by this FUNCTIONAL 400 .. 420 .. REPAIR PLAN .. SPECIFICATIONS .. GENERAL DESCRIPTION .. Board .. Board .. Board .. Module .. Board .. Assembly .. Board .. 1-6 SECTION 2 SPECIAL TOOLS AND TEST INTRODUCTION .. SPECIAL TOOLS AND TEST EQUIPMENT .. TEST PANELS AND 2-1 Page iv 400 SERIES MAINTENANCE MANUALP/N 190-00140-05 Rev. CSECTION TROUBLESHOOTING EQUIPMENT .. TROUBLESHOOTING TROUBLESHOOTING PROCEDURES .. Supply Checks .. Current Com Board .. Glideslope Nav Board .. Clock Check .. Internal Clock Check Main Internal Clock Check GPS Processor .. STATIC MESSAGES .. TESTING EXTERNAL CONNECTORS.

7 CONNECTOR I/O DESCRIPTIONS .. BLOCK DIAGRAM .. 3-15 SECTION 4 DISASSEMBLY AND REQUIRED TOOLS .. NAV DATA CARD REMOVAL AND UNIT DESIGN .. DISASSEMBLY PROCEDURE .. the Top Cover .. the CDU Assembly .. Disassemble the CDU Assembly .. the Main and Nav Chassis .. Faulty Boards from the Main Chassis Top Cavity .. Faulty Boards from the Main Chassis Underside Faulty Boards from the Nav Chassis .. REASSEMBLY .. MEMORY BATTERY the Memory 4-8400 SERIES MAINTENANCE MANUAL Page vP/N 190-00140-05 Rev. CSECTION 5 ALIGNMENT, CALIBRATION, AND .. TEST EQUIPMENT .. SIGNALS AND TEST Com Transceiver .. Standard Loads .. Standard Signals .. Standard Loads .. Standard Signals.

8 Receiver .. Standard Loads .. Standard Signals .. Standard Test Signals .. Standard Standard Test Signals .. Setup Page Fields .. Com Frequency .. Frequency Spacing .. SQ 250 .. SQ 833 .. Sidetone .. MIC Gain .. PROCEDURES .. Mode .. Testing .. Power Input Check .. RF Power Frequency Stability and Modulation Capability Test .. Carrier Noise Demodulated Audio Demodulated Audio 5-17 Page vi 400 SERIES MAINTENANCE MANUALP/N 190-00140-05 Rev. CSECTION 5 ALIGNMENT, CALIBRATION, AND TESTING (continued) Sidetone .. MIC Intercom Test .. Receiver Sensitivity .. TX Interlock .. AGC Selectivity (25 kHz Mode) .. Selectivity ( kHz Mode).

9 Volume Control (Audio Output) .. Audio Distortion Test .. Audio Frequency Response .. Receiver Audio Compressor Test .. Squelch Test .. Frequency Com Remote Transfer Input .. Receiver Final Tests .. Voice/Ident Audio Output Voice/Ident Audio Frequency Response .. Voice/Ident Audio Distortion .. VOR AGC .. VOR Audio Sensitivity .. Receiver Ident/Voice Tone Harmonic Distortion .. VOR Flag Sensitivity .. LOC Flag Sensitivity .. VOR/LOC Composite Test .. VOR Course Deviation Sensitivity .. Localizer Course Deviation Sensitivity .. TO-FROM Indicator .. Centering Accuracy .. Course Deviation Accuracy Test .. VOR OBS Bearing Accuracy .. Selectivity .. Spurious Response VOR/LOC.

10 5-31400 SERIES MAINTENANCE MANUAL Page viiP/N 190-00140-05 Rev. CSECTION 5 ALIGNMENT, CALIBRATION, AND TESTING (continued) Assembly I/O Tests .. Localizer Course Deviation Test .. To/From Deflection Output Characteristic Test .. To/From Deflection Accuracy Test .. Course Deviation Flag Output Characteristic Test .. Course Deviation Flag VOR/LOC Super Flag Output Test .. NAV Input Lines .. NAV OBI Outputs .. Nav Serial DME Outputs .. NAV Parallel DME Outputs .. Final Glideslope Course Deviation Output Characteristic Test .. Course Deviation Deflection Accuracy Test .. Course Deviation Flag Glideslope Superflag Output Test .. Receiver Sensitivity .. Centering Accuracy.