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BenQ G2220HD - 21.5" LCD Monitor, Service Manual, Page: 41 / 47

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BenQ G2220HD - 21.5

                                                                             

41

5.7 Trouble Shooting Guide 

Backlight can’t be turned on 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No raster? 

LED Green? 

Yes 

Yes 

Yes 

Backlight can’t be 

turned on. 

No 

Check power 

supply 

Is there high-level voltage on 

pin4 of IC501? 

No 

Is Ok R502? 

Check I/F board 

Yes 

R502 open 

No

Yes 

Is there instantaneously pulse wave on pin1, 

pin11, pin14 of IC501 at the moment of restart? 

No 

Is Ok IC501?

Yes 

U501, U502 fail   

No

IC501 fail 

Yes

Is ok T501, T502? 

T501, T502 fail 

Are connected rightly CN501, 

CN502, CN503 and CN504? 

No 

Connecting the 

output connector 

again   

No 

Check feedback circuit 

LI1, LI2, OV1, 

OV2

 

Yes 

END 

Is there 24Vdc 

voltage on pin9 of 

Yes 

Yes 

Summary of Contents for G2220HD - 21.5" LCD Monitor

Page 1: ...2009 12 18 Notice For RO to input specific Legal Requirement in specific NS regarding to responsibility and liability statements Please check BenQ s eSupport web site http esupport benq com to ensure...

Page 2: ...Characteristics 10 3 7 User Controls 10 3 8 Mechanical Characteristics 10 3 9 Pallet Shipment 11 4 Level 1 Cosmetic Appearance Alignment Service 12 4 1 Software Firmware Upgrade Process 12 4 2 Alignme...

Page 3: ...ics tests troubleshoot problems and align the BenQ product 1 1 Trademark The following terms are trademarks of BenQ Corporation Importance Only trained service personnel who are familiar with this Ben...

Page 4: ...ower cable immediately and consult your closed dealer z Always unplug the monitor before cleaning it Clean the cabinet with a clean dry cloth Apply non ammonia based cleaner onto the cloth not directl...

Page 5: ...Signal Interface Input Connector Analog D sub 15 Video Cable Strain Relief Equal to twice the weight of the monitor for five minutes Video Cable Connector DB 15 Pin out Compliant DDC 2B Video Signals...

Page 6: ...39 25 Non Preset 23 848x480 37 68 74 77 41 00 Non Preset 24 720x576 35 910 59 950 32 71 Non Preset 25 1024x768 I 35 52 43 48 44 9 Fail Safe Mode 26 1024x768 48 36 60 00 65 00 Preset 27 1024x768 56 48...

Page 7: ...Preset 82 1600x1280 79 5 59 9 171 75 Non Preset 83 1792X1344 83 57 59 9 203 25 Fail Safe Mode 84 1792X1344 105 290 75 00 257 75 Out of Range 85 1856X1392 86 485 59 934 217 25 Out of Range 86 1856X139...

Page 8: ...ypical 5ms Max 8ms Surface Treatment Anti glare 3H Hard coating 3H AG Haze25 Lamp 4 CCFL Outline Dimension 495 6 W X 292 2 H X 16 35 D typ 499 5 W X 292 6 H X 17 D typ Brightness uniformity Min 75 Typ...

Page 9: ...sine wave signal 1 KHz 0 7Vrms 3 5 5 Electrostatic discharge Requirements Item Condition Spec Remark Contact discharge 4KV Contact discharge 8KV Air discharge 8KV Electrostatic Discharge InnoLux SPEC...

Page 10: ...m2 Typical 300cd m2 Min 250cd m2 Typical 300cd m2 Contrast Ratio Min 600 1 Typical 1000 1 Min 700 1 Typical 1000 1 Viewing Angle Hor 170 Ver 160 Typical CR 10 Hor 170 Ver 160 Typical CR 10 Display Mod...

Page 11: ...BCS 7015A Black ABS PMMA Arm front HIGH GLOSSY 95 POLISHING 6000 BCS 7015A Black ABS PMMA Base HIGH GLOSSY 95 POLISHING 6000 MT11000 BCS 7015A Black ABS PMMA Function key HIGH GLOSSY 95 POLISHING 600...

Page 12: ...0 3 Kg Net 6 1 0 5Kg 509 6 175 392 9mm Package Items Spec Packaging Refer to ME PACKING SPEC Ink The ink shall not rub off after a suitable drying time Shipping Carton Type One Piece Construction Ship...

Page 13: ...ar side of monitor CONTROL KEY KEYS FUNCTION MENU A When OSD displays press MENU to return to previous level menu B When OSD isn t shown on screen press MENU to enter OSD interface C Press MENU to ent...

Page 14: ...the last status before AC off And monitor would always be off while AC off on in off mode 4 2 3 3 OSD Control The On Screen Display OSD shall be an easy to use icon based menu through keypad OSD butto...

Page 15: ...ower On OSD menu will be shown with F on the left top Select F for entering factory mode AUTO Level Automatically calibrate chip ADC parameter by using chip internal DAC GAIN ADC gain value OFFSET ADC...

Page 16: ...8 1440x900 1920x1080 And power saving signal etc 2 Confirm the above timing modes must be full screen and the picture must be normal Chroma Signal Generator VGA cable detector When VGA cable is not pl...

Page 17: ...17 Power Off 1W Off...

Page 18: ...18 5 Level 2 Disassembly Assembly Circuit Board Standard Parts Replacement 5 1 Exploded Diagram...

Page 19: ...Y ARM 1 ASSY BEZEL 1 ASSY PANEL 1 FOIL PET AL 140 40mm 2 SCREW P CROSS M4 10 2 KEYPAD 1 FOIL AL L50 W30 T0 09mm LE2294 1 ASSY BACK COVER 1 LE 21P8 LCD Monitor BEZEL 1 LOGO BENQ LE20D6 1 FNCTION KEY 1...

Page 20: ...20 1 Assemble the keypad 2 Assemble the panel with front bezel 3 Assemble chassis Plug in the LVDS 4 Plug in the lamp lines...

Page 21: ...21 5 Stick the foil 6 Stick the foil 7 Plug in the keypad cable 8 Assemble the back cover...

Page 22: ...22 9 Assemble the stand and screw the screws 10 Assemble the base...

Page 23: ...INGE LE21P8 1 LE 21P8 LCD Monitor ASSY PANEL 1 FOIL PET AL 140 40 mm 2 KEYPAD 1 FOIL AL L50 W30 T0 09mm LE2294 1 ASSY BASE BASE LE21P8 1 RUBBER FOOT 5 I F BOARD 1 POWER BOARD 1 SCREW M3 6 Zn Cc 6 H4 7...

Page 24: ...24 1 Disassemble the base 2 Unscrew the screws and disassemble the stand 3 Disassemble the front bezel 4 Disassemble the back cover...

Page 25: ...25 5 Remove the keypad cable 6 Pull out the lamp wire 7 Remove the foil 8 Remove the foil...

Page 26: ...26 9 Pull out the LVDS 10 Remove the chassis 11 Remove the keypad 12 Remove the panel...

Page 27: ...27 5 4 Block diagram Power Board...

Page 28: ...28...

Page 29: ...29...

Page 30: ...30...

Page 31: ...31 IF Board...

Page 32: ...32...

Page 33: ...33...

Page 34: ...34...

Page 35: ...35 5 5 Lay out 5 5 1 IF board lay out...

Page 36: ...36...

Page 37: ...37 5 5 2 P I Board lay out...

Page 38: ...d U502 work as Half bridge topology it is high efficient PWM switching During start up C520 C521 C522 C523 senses the voltage at the transformer secondary When OV1 OR OV2 reaches 13V Level the output...

Page 39: ...t connects to 5V and 24V output through R822 R825 R826 and There are output voltage sampling resistor When the sampling voltage more than 2 5V or less than 2 5V current of COMP IC802 will change this...

Page 40: ...utputs Brightness PWM signals to control CCFL brightness U105 RTD2555L 39 output PANEL_ENABLE to make Q104 conducted and then make Q101 conducted 5V flow to CN103 1 3 as Panel VDD U105 RTD2555L 20 out...

Page 41: ...502 Check I F board Yes R502 open No Yes Is there instantaneously pulse wave on pin1 pin11 pin14 of IC501 at the moment of restart No Is Ok IC501 Yes U501 U502 fail No IC501 fail Yes Is ok T501 T502 T...

Page 42: ...heck circuit if short Check F801 P801 RT 801 D801 Check pin7 of IC802 voltage about 16V CheckC810 D803 C807 Check pin2 of IC802 voltage about 3V Check primary OVP OLP and secondary feedback OVP circui...

Page 43: ...R822 R824 R825 R826 Check the R pin voltage of IC803 about 2 5V Check R832 R820 Check D803 C807 if short Change D803 C807 Check pin2 of IC802 voltage is 3V Check pin5 of IC802 voltage below 1 4V Chang...

Page 44: ...of CN101 Check power supply Of U108 Check Crystal of U108 Check CCFL Enable of U108 MCU Fail Check Check X101 Inverter Fail OK NG NG OK NG Check Reset Of U108 Check pin5 of CN101 Check R106 Q103 R105...

Page 45: ...Change LVDS Cable Check VLCD Is 5V Check Panel Enable Of U108 is High Check R107 R176 Q101 Q104 END Workmanship LVDS Cable NG Panel Fail Check LVDS Signals Check the HW Reset Of U108 Check the pins O...

Page 46: ...LVDS Cable Reinsert Change LVDS Cable Check the communication of the U108 and U105 Check the Pins of The U108 and U105 END Workmanship LVDS Cable NG Check SDO SCZ SCK SDO Reset NG NG NG OK OK OK Check...

Page 47: ...47 6 Dimmession Drawing...

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