CAUTION: DO NOT TOUCH THE CIRCUIT CARDS BEFORE YOU DO THE PROCEDURE FOR
_______ DEVICES THAT ARE SENSITIVE TO ELECTROSTATIC DISCHARGE. ELECTROSTATIC DISCHARGE CAN CAUSE DAMAGE TO THE CIRCUIT CARDS.
(4)
Do the procedure for devices that are sensitive to electrostatic discharge (AMM 20-41-02/201).
S 024-042
(5)
Remove the refuel valve relay card (AMM 28-21-31/401).
S 024-007
(6)
Remove the individual fuel quantity channel (IFQC) cards (AMM 28-41-15/401).
S 024-008
(7)
Remove the input/output (I/O) cards (AMM 28-41-16/401).
TASK 28-41-13-404-053
3. Fuel Quantity Processor Unit Circuit Cards Installation (Fig. 401)
_______________________________________________________
A. References
(1)
AMM 20-41-02/201, Electrostatic Discharge Sensitive Devices
(2)
AMM 28-21-31/401, Refuel Valve Relay Card
(3)
AMM 28-21-32/501, Volumetric Top Off Adjustment Card
(4)
AMM 28-41-15/401, Individual Fuel Quantity Channel Cards
(5)
AMM 28-41-16/401, Fuel Quantity Processor Input/Output Cards
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A
747-400
MAINTENANCE MANUAL
(6)
AIPC 28-21-52, Fig. 1
B.
Access
(1)
Location Zone 125 Area Below Forward Cargo Container Compartment, Left
(2)
Access Panel
125B Electronics Access Door
C.
Procedure
S 914-045
CAUTION: DO NOT TOUCH THE CIRCUIT CARDS BEFORE YOU DO THE PROCEDURE FOR
_______ DEVICES THAT ARE SENSITIVE TO ELECTROSTATIC DISCHARGE. ELECTROSTATIC DISCHARGE CAN CAUSE DAMAGE TO THE CIRCUIT CARDS.
(1)
Do the procedure for devices that are sensitive to electrostatic discharge (AMM 20-41-02/201).
S 424-051
(2)
Install the input/output (I/O) cards (AMM 28-41-16/401).
S 424-055
(3)
Install the individual fuel quantity channel (IFQC) cards
(AMM 28-41-15/401).
S 424-056
(4)
Install the refuel valve relay card (AMM 28-21-31/401).
S 714-057
(5)
Do this task: VTO Card Calibration Adjustment (AMM 28-21-32/501).
(6)
Close the door on the fuel quantity processor unit.
(7)
Close the electronics access door, 125B.
S 414-058
S 414-059
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A
747-400 MAINTENANCE MANUAL
S 864-060
(8)
Remove the DO-NOT-CLOSE tags and close these circuit breakers:
(a)
On the main power distribution panel, P6: 1) 6D5, FUEL QTY 1 2) 6D6, FUEL QTY 2
(b)
On the DC power distribution panel, P180: 1) 180M8, FUELING VALVE 2 2) 180M9, FUELING PWR - HOT BAT 3) 180C25, FUELING LTS PANEL 4) 180C26, FUELING LTS RECP
(c)
On the left power distribution center, P414: 1) 414F17, FUELING VALVE 2) 414F22, FUELING PWR
TASK 28-41-13-004-009
4. Fuel Quantity Processor Unit (FQPU) Removal (Fig. 401)___________________________________________
A. References
(1)
AMM 20-11-22/401, E/E Rack-Mounted Components
(2)
AIPC 28-21-52, Fig. 1
(3)
SSM 28-41-02, 28-41-03, 28-41-04, 28-41-05
(4)
WDM 28-41-12, 28-41-21, 28-41-22, 28-41-23, 28-41-24
B.
Access
(1)
Location Zone 125 Area Below Forward Cargo Container Compartment, Left
(2)
Access Panel
125B Electronics Access Door
C.
Procedure