# General Electric Service Bulletin GEnx-2B 73-0090: Revision R02 - Rights: © General Electric Company. Filed by the FAA in regulations.gov docket FAA-2021-0273; AD 2021-21-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [General Electric Service Bulletin GEnx-2B 73-0090](https://openairdocs.org/service-documents/ge/genx2b-73-0090.md) - Title as filed: GEnx-2B SB 73-0090 R02 - Pages: 17 - PDF: https://openairdocs.org/files/sha256/c2/d5/c2d581e1ff132684cf17ab00b90f5b9d345fdec94a322e52b86039146e7eb851 - Page: https://openairdocs.org/service-documents/ge/genx2b-73-0090/file/c2d581e1ff13 ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 GEnx-2B Service Bulletins (SBs) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards Date Printed: 2021/07/09 GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or reproduced without the express written consent of GE. Technical data is considered ITAR and/or EAR controlled; transfer of this data to a Non-US Person, without USG authorization, is strictly prohibited. Page 1 of 17 GEnx-2B SERVICE BULLETIN - 73-0090 R02 Revised:05/20/2021 SB 73-0090 R02 ENGINE FUEL AND CONTROL - ELECTRONIC ENGINE CONTROL (73-21-20) - REPLACEMENT OF INTEGRATED CIRCUIT MN4 ON MAIN CHANNEL BOARDS Issued: 12/17/2020 GE Designated: -CONFIDENTIAL- The information contained in this document is GE proprietary information and is disclosed in confidence. It is the property of GE and shall not be used, disclosed to others or reproduced without the express written consent of GE, including, but without limitation, it is not to be used in the creation, manufacture, development, or derivation of any repairs, modifications, spare parts, designs, or configuration changes or to obtain FAA or any other government or regulatory approval to do so. If consent is given for reproduction in whole or in part, this notice and the notice set forth on each page of this document shall appear in any such reproduction in whole or part. This technical data is considered subject to the Export Administration Regulations (EAR) pursuant to 15 CFR Parts 730-774. Transfer of this data by any means to a Non-U.S. Person, whether in the United States or abroad, without the proper U.S. Government authorization (e.g., License, exemption, NLR, etc.), is strictly prohibited. GE Aviation authorizes the Federal Aviation Administration to incorporate this document by reference in an Airworthiness Directive. Copyright (2021) General Electric Company, U.S.A. TRANSMITTAL INFORMATION REVISION 2 TO SERVICE BULLETIN 73-0090 Revision 2 is issued to update paragraphs 1., and 4., PLANNING INFORMATION APPENDIX - .A Revision 1 was issued January 28, 2021. The original was issued December 17, 2020. Revision bars in the left margin identify changes. 1. PLANNING INFORMATION A. Effectivity * * * GEnx-2B67, -2B67B, -2B67/P This Service Bulletin is applicable to all GEnx-2B engines. The electronic engine controls (EECs) VIN (P/N ), VIN 114E9849G1 2124M70P02 (P/N ), and VIN (P/N ) are affected114E9849G2 2124M70P03 114E9849G3 2124M70P04 by this Service Bulletin. B. Description This Service Bulletin provides instructions to replace the EEC MN4 bridge ball grid array (BGA) microprocessor. C. Compliance Category 2 GE recommends that you do this Service Bulletin under the following conditions based on the cycles since new (CSN) or cycles since repair (CSR) of the EEC MN4 microprocessors as follows: *Replace the EEC MN4 microprocessor after the MN4 microprocessor reaches 9,900 CSN (soft-time) but before it exceeds 11,000 CSN. *Thereafter, replace the EEC MN4 microprocessors after the MN4 microprocessor reaches 9,900 CSR (soft-time) but before it exceeds 11,000 CSR. NOTE:For the purposes of this Service Bulletin, EEC shop visit is the induction of the EEC into any FADEC International authorized repair shop. NOTE:EEC MN4 microprocessor replacement is limited to a maximum of three replacements for each main channel board (MCB). After three replacements, the MCB will need to be replaced. Impact A ### Page 2 GEnx-2B Service Bulletins (SBs) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards Date Printed: 2021/07/09 GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or reproduced without the express written consent of GE. Technical data is considered ITAR and/or EAR controlled; transfer of this data to a Non-US Person, without USG authorization, is strictly prohibited. Page 2 of 17 This recommendation is to address a condition that may affect Flight Safety. NOTE:A loss of thrust control (LOTC) may occur. NOTE:This Service Bulletin can be done in shop. This Service Bulletin is offered to improve the reliability or performance of your GE product, or to help prevent the occurrence of the event or condition described in this Service Bulletin. If the operator elects not to participate in the bulletin, that decision will be taken into consideration by GE in evaluating future product performance issues that may arise in the operator's fleet. D. Concurrent Requirements None. E. Reason (1) Objective: To rework a part, improve reliability, and reduce significant events. (2) Condition: An LOTC event has occurred due to an EEC MN4 microprocessor solder ball failure. (3) Cause: Accumulated thermal cycles of the EEC with age causes the solder ball to fail. (4) Improvement: The MN4 integrated circuit on the MCB will be removed along with the solder and will be replaced with a new solder and a new BGA. (5) Substantiation: Substantiation by analysis. F. Approval The data contained in this Service Bulletin has been reviewed by the FAA or authorized entity representing the FAA and the repair(s) and modification(s) herein comply with the applicable Aviation Regulations and are APPROVED for installation in the model(s) listed in this Service Bulletin. G. Manpower Refer to the attached FADEC International Service Bulletin FADEC3/73-093 (latest version). H. Weight and Balance Weight and balance are not changed. I. References (Use the latest version of these documents) GEnx-2B, Boeing 747-8 Aircraft Maintenance Manual (AMM) GEK 114119, GEnx-2B Engine Manual (EM) GEK 114122, GEnx-2B Engine Illustrated Parts Catalog (EIPC) GEK 114021, GEnx-2B Component Maintenance Manual (CMM), 73-23-15 FADEC International Service Bulletin FADEC3/73-093, ENGINE FUEL AND CONTROL - ECU Modification - Replacement of MN4 Microprocessor BGA on Main Channel Boards (MCB) J. Publications Affected None. K. Interchangeability Not applicable. L. Software Accomplishment Summary Not applicable. 2. MATERIAL INFORMATION A. Material - Price and Availability (1) Parts necessary to do this Service Bulletin: Refer to the attached FADEC International Service Bulletin FADEC3/73-093 (latest version). (2) Other Spare Parts: None. (3) Consumables: None. B. Industry Support Information Refer to the attached FADEC International Service Bulletin FADEC3/73-093 (latest version). C. Configuration Chart None. D. Parts Disposition None. E. Tooling - Price and Availability ### Page 3 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards None. 3. ACCOMPLISHMENT INSTRUCTIONS A. General (1) Remove the EEC (Figure 1). Removal instructions have not changed. Refer to the GEnx-2B EM, 72-00-00, DISASSEMBLY 001 or GEnx-2B, Boeing 747-8 AMM, 73-21-05, ELECTRONIC ENGINE CONTROL (EEC) - REMOVAL, TASK 73-21-05-000-801-G00. (2) Send the removed EEC (Figure 1) to FADEC International. Refer to the attached FADEC International Service Bulletin FADEC3/73-093 (latest version). (3) Install the EEC (Figure 1). Installation instructions have not changed. Refer to the GEnx-2B EM, 72-00-00, ASSEMBLY 001 or GEnx-2B, Boeing 747-8 AMM, 73-21-05, ELECTRONIC ENGINE CONTROL (EEC) - INSTALLATION, TASK 73-21-05-400-801-G00. EEC 6018983-00 EEC Location Figure l 4. APPENDIX - A VENDOR SERVICE BULLETIN SUMMARY TABLE Vendor Service ENGINE FUEL AND CONTROL - ECU Modification - Replacement of MN4 Microprocessor BGA on Bulletin Title: Main Channel Boards (MCB) GE Service GEnx-2B S/B 73-0090, Revision 2 Bulletin Number: Supplier Service FADEC3/73-093 Vendor: FADEC International GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data is Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 3 of 17 Person, without USG authorization, is strictly prohibited. ### Page 4 GEnx-2B Service Bulletins (SBs) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards Date Printed: 2021/07/09 GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or reproduced without the express written consent of GE. Technical data is considered ITAR and/or EAR controlled; transfer of this data to a Non-US Person, without USG authorization, is strictly prohibited. Page 4 of 17 Bulletin Number: Category: 2 Vendor CAGE Code: 3E6E4 Component Maintenance Manual (CMM): 73-23-15 CMM CAGE Code: 3E6E4 PARTS AFFECTED New GE Part Number Old GE Part Number New Vendor Part Number Old Vendor Part Number Part Name 2124M70P02 2124M70P02 114E9849G1 114E9849G1 Control, Electronic Engine 2124M70P03 2124M70P03 114E9849G2 114E9849G2 Control, Electronic Engine 2124M70P04 2124M70P04 114E9849G3 114E9849G3 Control, Electronic Engine NOTE:For interchangeability and/or material support, refer to the attached FADEC International Service Bulletin FADEC3/73-093 (latest version). ### Page 5 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC TO: Holders of ENGINE FUEL AND CONTROL-FADEC3 GEnx-2B Electronic Control Unit (ECU). FROM: FADEC International CAGE: 3E6E4 11-13 Rue Ampere 91344 MASSY - FRANCE Web: http://fadecinternational.net SUBJECT: FADEC3-73-093, ENGINE FUEL AND CONTROL - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB), Revision 0, dated Dec 17/2020. The subject Service Bulletin is attached to this letter of transmittal. SUMMARY: This Service Bulletin gives procedure to replace Integrated circuit MN4. REVISION HISTORY Basic Issue Dec 17/2020 Please direct any questions or comments to the address above. FADEC INTERNATIONAL PROPRIETARY INFORMATION EXPORT CONTROLLED DATA The technical data in this document (or file) is controlled for export under the US Goverment Export Administration Regulations (EAR), 15 CFR Parts 730-774, ECCN: 9E991, effective as of this issue date. This information must not be transferred to a foreign person without proper authorization of the U.S. Goverment. Violations may result in administrative, civil, or criminal penalties. GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 5 of 17 [Person, without USG authorization, is strictly prohibited. ### Page 6 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). FADEC INTERNATIONAL PROPRIETARY INFORMATION This information is owned by FADEC International and contains proprietary information of FADEC International. This information is copyrighted by the owner and is licensed to the recipient. This information may not be disclosed to anyone other than the recipient, or used for other than its intended purpose without express written consent of FADEC International. COPYRIGHT 2020 FADEC International. All rights reserved. EXPORT CONTROLLED DATA The technical data in this document (or file) is controlled for export under the US Government Export Administration Regulations (EAR), 15 CFR Parts 730-774, ECCN: 9E991, effective as of this issue date. This information must not be transferred to a foreign person without proper authorization of the U.S. Government. Violations may result in administrative, civil, or criminal penalties. 1. PLANNING INFORMATION A. Effectivity (1) This Service Bulletin applies to the following Electronic Control Units (ECUs): VIN 114E9849Gx (P/N 2124M70P0x) containing MCB P/N 392-207-904-0, 392-207-905-0, 392-207-906-0, 262197983-0905, 262197983-0906, 262197983-1905, 262197983-1906. Note #1: Here under are Main-Channel-Boards (MCB) that have had MN4 previously replaced. This is the best-known list at last revision of this Service Bulletin: ECU S/N MCB S/N Shop Received ECU S/N MCB S/N Shop Received date date (DD/MM/YYYY) (DD/MM/YYYY) FFFC1060 08G1155 02/08/2019 FFFC1225 11H0251 27/09/2018 FFFC1491 14J8339 24/10/2019 FFFG6732 15M6534 09/10/2018 NA (FI 07D0183 05/11/2018 N/A 17B6262 08/05/2019 Rotable) (FI Rotable) Note #2: The EEC/ECU level effectivity is based on the best available data. It is also allowable to perform this Service Bulletin on an affected subassembly that has been removed from a top-level unit. This Service Bulletin may also be performed on subassemblies sent individually that meet above criteria. Note #3: MN4 replacement is limited to a maximum of 3 replacements for each MCB. After 3 replacements, concerned MCB will need to be replaced. Dec 17/2020 FADEC3/73-093 Page 1 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 6 of 17 Person, without USG authorization, is strictly prohibited. ### Page 7 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). B. Reason (1) Objective This Service Bulletin authorizes the replacement of Integrated circuit MN4 on Main- Channel-Boards to prevent operational events related to solder ball fractures. (2) Condition A solder ball failure on the Integrated Circuit (MN4) on the MCB could initiate a systen effect that may result in a LOTC (3) Cause Aging of BGA (Ball Grid Array) solder balls degraded the integrity of the solder connection. (4) Improvement The Integrated Circuit (MN4) on the MCB will be removed along with the solder and will be replaced with new solder and a new BGA. (5) Substantiation Substantiation is by fleet experience. C. Description This Service Bulletin provides replacement instruction for the ECU MN4 Ball Grid Array (BGA) microprocessors. D. Compliance (1) Technical Compliance. Category 2. FADEC International recommends that you do this Service Bulletin as soon as possible without effect on revenue service but under the following conditions based on the cycles since new (CSN) or cycles since repair (CSR) of the ECU MN4 microprocessors as follows: (a) Replace the ECU MN4 Processors prior to 11,000 CSN (b) For ECU MN4 microprocessors that have accumulated more than 11,000 CSN, replace within 1 year of release of this SB (c) Thereafter, replace the ECUMN4 microprocessors at first ECU component shop visit prior to 11,000 CSR of the ECU MN4 microprocessors. Note: For the purposes of this Service Bulletin, ECU shop visit is the induction of the ECU into any FADEC International authorized repair shop. Dec 17/2020 FADEC3/73-093 Page 2 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 7 of 17 Person, without USG authorization, is strictly prohibited. ### Page 8 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). Note: MN4 replacement is limited to a maximum of 3 replacements for each MCB. After 3 replacements, the main channel board will need to be replaced. E. Approval This Service Bulletin with the part numbers listed in the paragraph 1.A., Effectivity is accepted by GE. GE has traceability to FAA engineering for acceptance of this service bulletin. F. Manpower (1) Approximately 4 man-hours is needed to complete this Service Bulletin. These hours do not include any Service Bulletins that need to be done to upgrade parts to the current configuration. (2) If you do not have the capability or if you want the Service Bulletin accomplished by authorized personnel, return the affected ECU and a Purchase Order to a substantiated repair facility. Send the affected ECU to this address: FADEC International FADEC International c/o BAE Systems c/o Safran Electronics & Defense 4250 Airport Expressway 13 rue Ampere Fort Wayne, IN 46809 91334 Massy Attn: Service Center Attn: Service Center G. Industry Support Please contact your FADEC International Customer Service Manager for details. H. Material Refer to Paragraph 3.A., Parts and Consumables. Material can be ordered from: FADEC International: OR Spare Orders c/o BAE System FADEC International 4250 Airport Expressway 11-13 rue Ampere Fort Wayne, IN 46809 USA 91334 Massy Attn: Customer Account France Representative-Spares Attn: Customer Account SITA/ARINC code: FWALMXD Representative-Spares Phone: +1-260-434-5600 SITA/ARINC code: PARHSCR E-mail: spares.enginecontrols@ Phone: + 33 1 64 14 83 31 baesystems.com E-mail: fadec.csc@safrangroup.com Dec 17/2020 FADEC3/73-093 Page 3 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 8 of 17 [Person, without USG authorization, is strictly prohibited. ### Page 9 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). Tooling TOOL NAME SUGGESTED SOURCE Oven, Thermal Commercial For Hot-cold thermal cycling during test. Must be capable of -54 + 2.5 °C (-65 ‡ 4.5 °F) to 105 + 2.5 °C (221 ‡ .5 °F) J. Weight and Balance Weight and Balance are not affected. K. References GEnx-2B SB 73-0090, ECU CMM 73-23-15, MCB PRM 73-23-56, PROPRIETARY PRACTICES MANUAL 73-20-23 or 73-20-23A. L. Publications Affected None. Dec 17/2020 FADEC3/73-093 Page 4 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 9 of 17 Person, without USG authorization, is strictly prohibited. ### Page 10 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). 2. ACCOMPLISHMENT INSTRUCTIONS. ACCOMPLISHMENT INSTRUCTIONS SHOULD ONLY BE PERFORMED BY FADEC INTERNATIONAL AUTHORIZED PERSONNEL. Direct correspondence to: FADEC International: CS-Customer.Service@baesystems.com fadec.csc@safrangroup.com BAE Systems Safran Electronics & Defense 1098 Clark Street 11-13 rue Ampere Endicott, NY 13760 91334 Massy USA France Attn: Commercial Product Support OR Attn: Customer Product Support Website: www.baesystems-ps.com/ Phone: +33 1 64 14 83 31 customersupport A. Equipment Protection. CAUTION: SUBASSEMBLIES OF THE EQUIPMENT CAN CONTAIN ESDS DEVICES (MICROCIRCUITS, SEMICONDUCTORS, AND FILM RESISTORS) THAT ARE SENSITIVE TO VOLTAGES MADE BY ELECTROSTATIC DISCHARGE. OBEY ESDS PRECAUTIONS WHEN YOU HANDLE SUBASSEMBLIES THAT HAVE THE ESD SYMBOL. THESE PRECAUTIONS ARE APPLICABLE TO THE FULL SUBASSEMBLY WHICH CONTAINS ESDS DEVICES. ATTENTION DESERT ELITICAL ELECTROSTATIC SENSITIVE DEVICES WHEN ESDS SUBASSEMBLIES ARE NOT INSTALLED IN THE UNIT, THEY MUST BE KEPT OR MOVED IN MATERIALS THAT ARE ELECTRICALLY CONDUCTIVE, AND MUST NOT BE PUT IN NON-CONDUCTIVE PLASTIC BAGS. STATIC SHIELD BAGS, OR THEIR EQUIVALENT, ARE THE CORRECT PROTECTIVE MATERIALS TO KEEP OR MOVE SUBASSEMBLIES. REFER TO THE GENERAL PRACTICES MANUAL, CHAPTER 73-60-00, FOR SPECIAL PROCEDURES FOR ESDS SUBASSEMBLIES. CAUTION: SUBASSEMBLIES OF THE EQUIPMENT CAN CONTAIN MOISTURE SENSITIVE DEVICES THAT CAN BE DAMAGED DURING SOLDERING OPERATIONS. OBEY MSD PRECAUTIONS IN THE GENERAL PRACTICES MANUAL, CHAPTER 73-61-00, PRIOR TO SOLDERING ANY MSD. Dec 17/2020 FADEC3/73-093 Page 5 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 10 of 17 [Person, without USG authorization, is strictly prohibited. ### Page 11 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). B. Incoming Inspection Use the steps that follow to examine ECU. (1) If the Part Number is not inside scope of the Effectivity paragraph or SB 73-0090 is on the Service Bulletin label and the cycle limitation has not been violated as per compliance section, this Service Bulletin is not necessary. If the PN is listed, continue to paragraph (2). (2) If the ECU and/or MCB Serial Number is listed in Note #1 of the Effectivity paragraph and cycle limitation in Compliance section has not been violated, the Service Bulletin is not necessary. Otherwise, continue to Step 2.C. C. Disassembly Use the steps that follow to disassemble the ECU. CAUTION: DISCARD ALL SCREWS AFTER USE. ALWAYS USE NEW SCREWS. LOCKING FEATURES CAUSE DAMAGE TO SCREW-THREADS. (1) Remove the Rear Cover. Refer to CMM 73-23-15 for DISASSEMBLY Procedures. (2) Examine the MCBs for their Serial Numbers and presence of SB 73-0090 accomplishment label. Refer to Figure 2 for location of the Serial Number and accomplishment label. -If the Serial Number is listed in Note #1 of effectivity paragraph and cycle limitation in compliance section has not been violated this Service Bulletin is not necessary for these MCB. -If SB 73-0090 accomplishment label is present on one or both MCB and cycle limitation in compliance section has not been violated, this Service Bulletin is not necessary for these MCB. -Remove the MCB or MCBs for which SB 73-0090 has to be applied. Refer to CMM 73-23-15 for DISASSEMBLY procedures. -If none MCB need application of SB 73-0090, then continue to step 2.E. and reassemble the ECU. Dec 17/2020 FADEC3/73-093 Page 6 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 11 of 17 Person, without USG authorization, is strictly prohibited. ### Page 12 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). D. Repair NOTE: All soldering must be complete within 24 hours of removing the MCB from the oven. If necessary, bake the MCB again. (1) Remove Cover, Card rails and stiffeners. Refer to PRM 73-23-56 DISASSEMBLY. (2) Remove and replace Integrated circuit MN4 (P/N 620-076-017-0). (Refer to Figure 1). This repair will be performed using the following internal FADEC International procedures: Proprietary Practices Manual 73-20-23. OR Proprietary Practices Manual 73-20-23A. (3) Recoat the repaired areas with Type SR Conformal coating. Refer to PRM 73-23-56 REPAIR (4) Install Cover, Card rails and stiffeners. Refer to PRM 73-23-56 ASSEMBLY. (5) Mark MCB with polyimide SB accomplishment label (approx. 0.1875 in. X 1 in. (approx. 4.762 mm X 25.4 mm) with 73-0090 and date of application. Refer to Figure 2 for approximate label location. Trim label to fit as necessary. Refer to the GENERAL PRACTICES MANUAL 73-30-16. If some 73-0090 label are already present, do not remove them, but put additional label side by side. (6) Test and program the MCB. (a) Run 20 unpowered temperature cycles of two hours duration each Temperature: - Cold -54 +2.5 °C (-65 t4.5 °F) - Hot 105 2.5 °C (221 ‡4.5 °F) - Timing (1 cycle in 2 hours): 44 13 minutes at stabilized cold temperature - 16 3 minutes transition cold to hot (at 10 +2 °C (18 +3.6 °F) per minute) 44 +3 minutes at stabilized hot temperature 16 +3 minutes transition hot to cold (at 10 ‡2 °C (18 +3.6 °F) per minute) (b) Program MN4 per PRM 73-23-56 Appendix A procedure or equivalent process and equipment. (c) Test per PRM 73-23-56 TESTING AND FAULT ISOLATION Section. Dec 17/2020 FADEC3/73-093 Page 7 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 12 of 17 Person, without USG authorization, is strictly prohibited. ### Page 13 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). E. Assembly Use the steps that follow to assemble the ECU. (1) Reinstall the MCBs. Refer to CMM 73-23-15 for ASSEMBLY procedures. (2) Install the Rear Cover on the ECU. Refer to CMM 73-23-15 for ASSEMBLY procedures. F. ECU Testing. For return to service, do a complete ATP at ROOM, COLD, and HOT temperatures. Refer to the TESTING AND FAULT ISOLATION section of CMM 73-23-15. G. Service Bulletin Identification Plate Marking. Use a ballpoint pen to mark the Service Bulletin Identification Plate as follows: 73-0090. Dec 17/2020 FADEC3/73-093 Page 8 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 13 of 17 Person, without USG authorization, is strictly prohibited. ### Page 14 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). MN4 Location of MN4 Figure 1 Dec 17/2020 FADEC3/73-093 Page 9 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 14 of 17 [Person, without USG authorization, is strictly prohibited. ### Page 15 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). PART NUMBER LABEL SERIAL NUMBER LABEL SB ACCOMPLISHMENT LABEL AREA Part Number and Serial Number Locations Figure 2 Dec 17/2020 FADEC3/73-093 Page 10 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 15 of 17 Person, without USG authorization, is strictly prohibited. ### Page 16 (OCR) GEnx-2B Service Bulletins (SBS) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards FADEC SERVICE BULLETIN ENGINE FUEL AND CONTROL - Electronic Control Unit (73-00-00) - ECU Modification - Replacement of MN4 BGA microprocessor on Main Channel Boards (MCB). 3. MATERIAL INFORMATION. A. Parts and Consumables. (1) Parts necessary to do this Service Bulletin: PART NUMBER QTY/ PART NAME UNIT $ PKG LEAD TIME ECU PRICE QTY DAYS 620-076-017-0 2 Integrated circuit (MN4) (*) () - NOTE: * FADEC International will quote the price of these parts. Pricing is available. (2) Future spare parts. None. (3) Consumables. None. B. Configuration Chart Configuration Chart is not provided because there is no change to the defined ECU hardware configuration. C. Interchangeability. Modified ECUs are interchangeable with non-modified ECUs. Modified MCBs are interchangeable with unmodified MCBs. D. Parts Disposition. None. Dec 17/2020 FADEC3/73-093 Page 11 of 11 FADEC INTERNATIONAL PROPRIETARY INFORMATION - Subject to the restrictions on the first page GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or Date Printed: reproduced without the express written consent of GE. Technical data Page 2021/07/09 considered ITAR and/or EAR controlled; transfer of this data to a Non-US 16 of 17 Person, without USG authorization, is strictly prohibited. ### Page 17 GEnx-2B Service Bulletins (SBs) SB 73-0090 R02 ENGINE FUEL AND CONTROL - Electronic Engine Control (73-21-20) - Replacement of Integrated Circuit MN4 on Main Channel Boards Date Printed: 2021/07/09 GE PROPRIETARY INFORMATION - Not to be used, disclosed to others or reproduced without the express written consent of GE. Technical data is considered ITAR and/or EAR controlled; transfer of this data to a Non-US Person, without USG authorization, is strictly prohibited. Page 17 of 17 GE Designated: - CONFIDENTIAL Subject to the restrictions on the media --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.