20-41-02
 ALL  ú ú 01 Page 202 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 B. Procedure - Printed Circuit Boards with the STATIC SENSITIVE placards -
Removal
 NOTE:____ The placards on the outer area of the card files show the cards
 that contain the ESDS printed circuit boards that are LRU's.

 S 862-060
 CAUTION: MAKE SURE YOU KEEP CONTAMINATION OR UNWANTED MATERIAL AWAY FROM THE
_______ SENSITIVE DEVICE. CONTAMINATION OR UNWANTED MATERIAL NEAR THE SENSITIVE DEVICE CAN CAUSE A MALFUNCTION IN THE SENSITIVE DEVICE.
 (1)  Remove the system electrical power with the applicable Removal/Installation procedure.
 S 722-056
 WARNING: USE A WRIST STRAP WITH A MINIMUM GROUNDING LEAD RESISTANCE OF
_______ 250 KILOHMS AND A MAXIMUM OF 1.5 MEGOHMS. USE OF A LOW RESISTANCE WRIST STRAP CAN CAUSE INJURY TO PERSONS IF A HIGH VOLTAGE SOURCE IS TOUCHED.
 (2)  Do these steps to do a test of the wrist strap resistance:
 (a)  
Use an ohmmeter to make sure the wrist strap assembly has a minimum resistance of 250 kilohms and a maximum of 1.5 megohms.

 (b)  
Put the wrist strap on your wrist.

 (c)  
Use an ohmmeter to make sure the resistance is less than 10 megohm.

 S 422-061
 (3)  Connect the wrist strap into the ELECTROSTATIC GROUND JACK of the card file.
 S 862-005
 CAUTION: THE GROUNDING LEAD ON THE WRIST STRAP MUST TOUCH THE
_______ SKIN TO GIVE THE PROTECTION THAT IS NECESSARY. FAILURE TO USE THE WRIST STRAP CORRECTLY CAN CAUSE DAMAGE TO THE ESDS PRINTED CIRCUIT BOARDS.
 (4)  
Attach the wrist strap correctly on the person that will remove the printed circuit board.

 (5)  
Open the access door on the card file, if there is an access door.

 S 032-007

 (6)  
From the location decal, find the printed circuit board to be removed.

 S 012-006
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 20-41-02
 ALL  ú ú 01 Page 203 ú Oct 10/95
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 S 022-008
 (7)  
Use the top and bottom (or left and right) extractors on the printed circuit board to remove it from the card file.

 S 862-010

 (8)  
Put the printed circuit board in the conductive bag or the container with the ESDS placard.

 S 862-009
 CAUTION: DO NOT USE STAPLES OR ADHESIVE TAPES TO CLOSE THE CONDUCTIVE
_______ BAGS. FAILURE TO CLOSE THE CONDUCTIVE BAGS CORRECTLY CAN CAUSE DAMAGE TO THE PRINTED CIRCUIT BOARD.
 (9)  Use an ESDS or a 100% cotton twine to close the conductive bag.
 NOTE: The printed circuit boards in a conductive bag must be put in
____ a rigid container to make sure the conductive bag stays in a satisfactory condition.
 S 862-011
 (10)
 Close the access door to the card file.

 S 862-012

 (11)
 Remove the wrist strap.

 TASK 20-41-02-402-054
 3. ESDS Printed Circuit Boards - Installation
__________________________________________
 A. Equipment
 (1)  
Conductive Bags (Commercially Available)

 (2)  
Conductive Plastic Carrier (Commercially
 Available)

 (3)  
Ohmeter

 (4)  
Wrist Straps, Conductive (Commercailly
 Available)

 (5)  
100% Cotton Twine - Commercially Available

 (6)  
ESDS Labels

 (a)  
JEDEC International Label - multi-source

 (b)  
3M - No. 7102

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 20-41-02
 ALL  ú ú 01 Page 204 ú Feb 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
 B.  Procedure - Printed Circuit Boards with a STATIC SENSITIVE Placard -Installation
　
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