AOC P/N : 41A50-144 service manual U200-DATA Output, PANEL-POWER Circuit, Mainboard

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PANEL-POWER CIRCUIT

check R225 should have response from 12V to 0V When we switch the power switch from on to off

OK,R225 have response

NG

Check the PPWR panel power relative circuit, R223, Q200,U202(pin 5,6,7,8)

In normal operation, when LED =green, R223 should =0 v,

If PPWR no-response when the power switch Turn on and turn off, replace the U200-GMZAN1

Measured the U202 pin 5,6,7,8= 5 V?

OK

OK

NG, no Voltage

Yes

Check U202 pin 1,2,3,4= 5V

Replace U202 ( Nmos, SI9933)

NG

Check U304 relative circuit.(R905,T300..)

INVERTER Control Relative Circuit

Measured the inveter connector CN303 Pin 1=12V, pin 3 on/off control=5V (on)

NG, still no screen

Replace INVERTER to new-one, and Check the screen is normal ??

OK

NG

NG

Check the Bklt-On relative circuit, R315, Q304, R311, In normal operation, when LED =green,

R315 Bklt-On should =0 v,

If Bklt-On no-response when the power switch turn on-off, Replace the MCU

Replace INVERTER-module & Re-do white balance

OSCILLATOR BLOCK

Measured U201 Oscillator output R215= 50mhZ ?

OK, has transition

Measured X300 Crystal output R340= 20mhZ ?

OK

U200-DATA OUTPUT

Measured PCLK(L207) PVS,PHS (pin 73,74 from U200 ) Is there have any transition? Pclk around 47MHz to 57MHZ , PVS=60.09Hz , PHS around 67 KHz ??(refer to input signal=640x480@60 Hz 31k, and LED is green)

OK

NG,no transition

Replace Oscillator U201

NG,no transition

Replace Crystal X300

NG , no transition

Replace GMZAN1 (U200) or replace

MAINBOARD.

If MainBoard being replace , please do the DDC – content reprogrammed

16

Image 17

Contents

Spectrum Series SEP Table of Contents LCD-PANEL Specifications for LCD MonitorGeneral specifications Interface Connectors Monitor Block DiagramLCD Monitor Description AC-IN AdapterAssembly Precaution Precautions and NoticesOperating Precautions Storage PrecautionsPIN no Description RED Operating InstructionsAdjustment Method AdjustmentAdjustment Conditions and Precautions Adjust 6500 color-temperature Front Panel Control Knobs OSD-INDEX Explanation CIRCUIT-DESCRIPTIONInput not Support CHI-MEI Panel M170E1MODULE-TPYE Component SIMPLE-INTRODUCTION about LM700 chipset Panel Software Flow Chart Power-On Subrotine ChartSET factory mode flag Clear factory mode flagII. Main Subrotine Loop No Screen Appear Interface-Board Trouble-Shooting chartMainboard PANEL-POWER CircuitU200-DATA Output Check Oscillator Block as above Keyboard Block check POWER-BLOCK check END Panel Luminance WAS Down There is an interferences in DOS ModeCorporation Inverter -MODULE Spec &Trouble Shooting ChartFunction Load Circuit M P O C O R P O R a T I O N Trouble Shooting of CHI-MEI Inverter DIVTL0037-D42 Part List Part Part Number QTY Description Supplier Remark Name Trouble Shooting Hight Voltage Protection Enbale Abnormality Transformer Abnormality Check U101 PIN4NO Freq ~70KHZ Part number 80AL17-1-CH Black, 80AL17-2-CH WhitePage Reference Part Quantity Cat.NO IV. Adapter BOM List Part no AL15-2-LIPCB PCB for CH-1205 Revd PCS For Front Heatsink No Voice Output AUDIO-MODULE Trouble shooting chartII. Sound Distortion Audio BOMGMZAN1 Analog-to-Digital Converter Pin DescriptionPIN # Name DescriptionHost Interface HIF / External On-Screen Display Clock Recovery / Time Base Conversion PIN # TFT Panel InterfaceName Description 2pxl/clk 1pxl/clk TFTTest Pins Typical Stand-alone Configuration System-level Block DiagramNative Operating ModesSlow Dclk ZoomSource Stand Alone DownscalingDestination Stand Alone Overall Architecture Clock Recovery CircuitFunctional Description Clock Recovery Circuit Sampling Phase Adjustment Clock Recovery CharacteristicsSource Timing Generator Minimum Typical MaximumAnalog-to-Digital Converter 2.3.1 Pin Connection ADC CharacteristicsPin Connection for RGB Input with Hsync/Vsync Pin Connection for RGB Input with Composite SyncDisplay Mode Support Sync. Signal SupportInput Timing Measurement Source Timing MeasurementIRQ-Generation Conditions IRQ Event Remark IRQ ControllerData Path Scaling Filter TFT Panel Interface Timing SpecificationGamma Table RGB OffsetPCLKB*4 Pclk *1Hsync width in TFT Vsync width and display position in TFTHorizontal size in TFT One pixel per clock mode in TFT Power ManagerState 1 Power On State 0 Power OffState 2 Panel Drive Enabled State 3 Panel Fully ActiveHost Interface Panel Interface Drive StrengthPanel Interface Pad Drive Strength Value 4 bits Drive Strength in mASerial Communication Protocol Timing Diagram of the gmZAN1 Serial CommunicationOn-Screen Display Control GmZAN1 Serial Channel Specification Parameter Min Typ MaxMulti-Function Bus MFB On-Chip OSD Controller OSD Color MapTclk Input Tclk SpecificationDC Electrical Characteristic Parameter Min Typ Max Electrical CharacteristicsAbsolute Ratings Parameter Min Typ Max PvddMechanical of Cabinet Front DIS-ASSEMBLY T780KMGHBAA0A Specification Parts List of CabinetParts List of Cabinet continue Location CBPC780GM Specification Parts List of Conversion BoardLocation AI780GM Specification Location AI780GM SMD EC 22UF 16V 85C Csize KEPC780EK Parts List of KEY PC BoardParts List of Audio Board Parts List of DC-POWER BoardInverter Module Power System and Consumption CurrentAdapter Module PCB Layout TOP-LEVEL Flow Schematic DiagramII. GMZAN1 Block Lvds Block MCU Block Power Block KBL405G Adapter Schematic CH-1205C1,C2,C4 --- 1uF/50V