8.1 RELIABILITY FAULTS:

BUTTON ON DISPLAY DOESEN'T WORK

DIAGNOSIS 1


PROCEDURE 1



Step 1

Lever off screw cover. 

Step 2

Unscrew. 

Step 3

Push the top cover forward. 

Step 4

Take away the top cover. 

Step 5

Disconnect the terminal of display PCB. 

Step 6

Unscrew and remove the display PCB. 

PROCEDURE 2


CHECK AND TEST 2

Step 1

Check if buttons on display work or not. 

DIAGNOSIS 2


CHECK AND TEST 3

Step 1

Unscrew the cover of mainboard. 

Step 2

Remove the mainboard box. 

Step 3

Separate the mainboard box. 

Step 4

Check if terminal in PCB area is inserted to final position. 

Step 5

Check if terminal in display area is inserted to final position. 

Step 6

Check if wire orders in PCB area and display area are correct or not. Photoes on the right show correct wire order. 

DIAGNOSIS 3



PROCEDURE 3


Step 1

Cut off the wire. 

Step 2

Peel off the sleeves. 

Step 3

Check to ensure proper wire order and connect them. 

Step 4

Tin soldering. 

Step 5

Cover connecting point with electrical tape. 

CHECK AND TEST 4

Step 1

Check if buttons on display work or not. 

DIAGNOSIS 4


CHECK AND TEST 5

Step 1

Measure resistance of wires in foam to check if wire connection in foam are correct or not. 


DIAGNOSIS 5


PROCEDURE 4


Step 1

Unsecrew and remove PCB from the box. 

Step 2

Prize off the buckle and disconnect the terminal. 

PROCEDURE 5


CHECK AND TEST 5

Step 1

Check if buttons on display work or not. 

DIAGNOSIS 5


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