420 Series
2-25
Procedure 5
Replacement Check
The FL, FL inverter board, LCD module, and system board are connected to the display
circuits. Any of these components may be damaged. Refer to Chapter 4, Replacement Proce-
dures, for instructions on how to disassemble the computer and then perform the following
checks:
If the FL does not light, perform Check 1.
If characters are not displayed clearly, perform Check 3.
If some screen functions do not operate properly, perform Check 3.
If the FL remains lit when the display is closed, perform Check 4.
Check 1
Replace the FL with a new one and test the display again. If the problem still
exists, perform Check 2.
Check 2
Replace the FL inverter board with a new one and test the display again. If the
problem still exists, perform Check 3.
Check 3
Replace the LCD module with a new one and test the display again. If the
problem still exists, perform Check 4.
Check 4
Replace the display switch with a new one and test the display again. If the
problem still exists, perform Check 5.
Check 5
Replace the display cable with a new one and test the display again. If the
problem still exists, perform Check 6.
Check 6
The system board may be damaged. Replace the system board with a new one.
Содержание 420CD
Страница 22: ...420 Series 2 3 Figure 2 1 Troubleshooting flowchart ...
Страница 172: ...420 Series B 1 Appendix B Board Layout B 1 System Board Front View Figure B 1 Board layout front ...
Страница 173: ...B 2 420 Series B 2 System Board Back View Figure B 2 Board layout back ...
Страница 197: ...E 2 420 Series E 3 German GR Keyboard Figure E 3 GR keyboard E 4 French FR Keyboard Figure E 4 FR keyboard ...
Страница 198: ...420 Series E 3 E 5 Spanish SP Keyboard Figure E 5 SP keyboard E 6 Italian IT Keyboard Figure E 6 IT keyboard ...
Страница 199: ...E 4 420 Series E 7 Scandinavian SC Keyboard Figure E 7 SC keyboard E 8 Swiss German SL Keyboard Figure E 8 SL keyboard ...