![Samsung 720N - SyncMaster - 17](http://html.mh-extra.com/html/samsung/720n-syncmaster-17-lcd-monitor/720n-syncmaster-17-lcd-monitor_service-manual_350483015.webp)
4 Troubleshooting
4-5
4-5 Backlight can't be turned on
LED lamp is OK
No backlight
No power supply to
inverter
Check the cable that from
I/F BD to P/I BD is ok
Check power supply
Replace U501, U502
Yes
Is there 14V
voltage on pin 3,4
of T501, T502
U501, U502 fail
Yes
Yes
No
Is there PWM
signal on pin 4 of
IC501
Check I/F BD
No
Yes
Is there High level
voltage on pin4 of
IC501
Check I/F BD
No
Yes
Vsense voltage
2.9V
Lamp connector opened
No
No
Are there PWM
signal on pin1,
pin15 of IC501
IC501 failure
No
Yes
Pin 5 of IC501
voltage is Low level
Feedback circuit failure
Yes
Check R523, D504,
R529, D507, R528, R533
Yes
Yes
Pin 5 of IC501
voltage is high level
voltage
IC501 protected
END
Yes
Check D505, D506,
D510, R522, R521, C520
Yes
No
Yes
No
Содержание 720N - SyncMaster - 17" LCD Monitor
Страница 6: ...1 Precautions 1 4 Memo ...
Страница 20: ...5 Exploded View Parts List 5 2 Memo ...
Страница 23: ...7 Block Diagrams 7 1 7 Block Diagram 7 1 Power tree ...
Страница 24: ...7 Block Diagrams 7 2 7 2 Mainboard part 7 3 IP Board Part SMPS Part ...
Страница 26: ...Memo 7 Block Diagrams 7 4 ...
Страница 27: ...8 Wiring Diagram 8 1 8 Block Diagram ...
Страница 28: ...Memo 8 Wiring Diagram 8 2 ...
Страница 30: ...9 Schematic Diagrams 9 2 9 2 INPUT ...
Страница 31: ...9 Schematic Diagrams 9 3 9 3 TSUM16AL ...
Страница 32: ...9 Schematic Diagrams 9 4 9 4 POWER ...
Страница 33: ...9 Schematic Diagrams 9 5 9 5 INVERTER ...
Страница 34: ...9 Schematic Diagrams 9 6 9 6 KEYPAD ...
Страница 37: ...10 Operating Instructions and Installation 10 3 10 3 Monitor Assembly ...
Страница 43: ...12 PCB Diagram 12 1 12 PCB Diagram 12 1 Main Board 12 1 1 Main Board Top Layer 12 1 2 Main Board Bottom Layer ...
Страница 44: ...12 PCB Diagram 12 2 12 2 Power Board 12 2 1 Power Board TOP Layer 12 2 2 Power Board BOTTOM Layer ...
Страница 47: ...13 Circuit Descriptions 13 3 13 1 3 IP Board Part Power Schematic Diagrams ...
Страница 56: ...14 Reference Infomation 14 8 Memo ...