NEC MultiSync 20WGX2 Series Service Manual page 92

TROUBLE SHOOTING
TABLE OF CONTENTS
Page
1. No Display on Screen (Screen is Black, Color of LED is Amber) ...................................6-2
2. Nothing Display on Screen (Screen is Black, Color of LED is Blue) ..............................6-3
3. Checking the Back Light Unit ..........................................................................................6-5
4. Abnormal Screen .......................................................................................................... 6-6
5. Abnormal OSM Display ..................................................................................................6-7
5.1 OSD Adjust Problem ......................................................................................................6-7
6. Abnormal Plug and Play Operation ................................................................................6-8
6.1 Abnormal DDC2 (D-Sub) ...............................................................................................6-8
6.2 Abnormal DDC2 (DVI) ....................................................................................................6-8
7. Checking the Interface Circuit of Sync Signal .................................................................6-8
7.1 Checking the Control Circuit of Horizontal Sync Pulse ...................................................6-9
7.2 Checking the Control Circuit of Vertical Sync Pulse .......................................................6-9
8. Checking the Resolution Change IC Movement ........................................................... 6-10
9. Checking the DC/DC converter circuit .......................................................................... 6-11
10. No Power On ................................................................................................................ 6-12
11. Check the USB Hub Circuit .......................................................................................... 6-13
11.1 HUB is not Recongnize ................................................................................................ 6-13
11.2 Connection Apparatus is not Recognize ...................................................................... 6-14
11.3 Connection Apparatus does not Work ......................................................................... 6-15
11.4 Check the USB IC ....................................................................................................... 6-16
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