NEC LCD1501-BK Service Manual page 47

TROUBLESHOOTING
TABLE OF CONTENTS
Page
1. No display of screen (Screen is black, color of LED is amber) ........................................ 6-2
2. Nothing displays on screen (Screen is black, color of LED is green) .............................. 6-3
3. Checking the back light unit ............................................................................................. 6-6
4. Abnormal screen .............................................................................................................. 6-7
5. Abnormal plug and play operation ................................................................................... 6-8
5.1 Abnormal DDC2 ............................................................................................................. 6-8
6. Checking the interface circuit of sync signal .................................................................... 6-9
6.1 Checking the control circuit of horizontal sync pulse ..................................................... 6-9
6.2 Checking the control circuit of vertical sync pulse .......................................................... 6-10
7. Checking the resolution change IC movement ................................................................ 6-11
8. No power on ..................................................................................................................... 6-12
9. Checking the operation of CPU ........................................................................................ 6-13
6-1