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LG Electronics U250 service manual Trouble Shooting

Models: U250

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4. TROUBLE SHOOTING

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LG Electronics U250 service manual Trouble Shooting

Contents

U250/KU250 Table Of Contents Page Purpose Regulatory InformationPictures Interference and AttenuationElectrostatic Sensitive Devices Specification System OverviewEnvironment Accessory Transmitter GSM ModeUsable environment Radio PerformanceCase of DCS a 1710, B Case of PCS a 1850, B Power Tolerance Transmitter Wcdma Mode Specification3Receiver GSM Mode Receiver Wcdma Mode Current Consumption U250/KU250 Current ConsumptionStand by Voice Call Level ChangeBattery BAR Indication StandbyTest Item Specification Sound Pressure LevelCharging Block diagram of RF part General DescriptionTechnical Brief GSM Mode Antenna Switch Module Control logicGSM Receiver Technical Brief RTR6275 RX feature GSM Transmitter GSM Transmitter matchingUmts Mode ReceiverTransmitter RTR6275 IC functional block diagram LO generation and distribution circuits Off-chip RF ComponentsWcdma PAM U103 WS2512-TR1G Vctcxo X100 DSA321SCE-19.2M Front-End Module U500 D5011Front End Module control logic Pmic Functional Block Diagram U300 PM6650-2M UsbotgMSM6245 Interface PM6650 Block Diagram GSM PAM Schematic GSM PAM U101 SKY77318Umts DuplexerFL104ACMD-7602 Wcdma Rx SAW Filter Specification Umts Rx RF filter FL103 EFCH2140TDE1Bluetooth M100 LBRQ-2B43A MSM6245 Bluetooth BasebandDigital BasebandDBB/MSM6245 General DescriptionPM6650 RTR6275Block DiagramMSM6245 Nand Flash512Mbit 76inch Wcdma R99 features SubsystemMSM6245ARM Microprocessor Subsystem GSM features Gprs featuresEdge features MSM6245 device audio processing features Supported interface featuresMSM6245 microprocessor subsystem Supported multimedia features Video telephony services QvideophoneTMQcameraTM QtvTMSummary of MSM6245 device features Description of RF configurations Mode Select and Jtag Interfaces Stereo Wideband CodecVocoder Subsystem General-Purpose Input/Output Interface UartUSB Power Block General2. PM6650 12 PM6650 Functional Block Diagram 13 U250/KU250 Battery Bar DisplayStand By Condition Charging controlTrickle Charging Parameter Min Typ Max Unit Trickle Current 100Constant Current Charging Constant Voltage ChargingExternal memory interface Table#1. External memory interface512Mb 64MBDATA310 DQM3011 H/W Sub System RF InterfaceRTR6275WCDMATx, GSMTx/Rx Others MSM Sub System Usim InterfaceGPIOMap Name Table. Uart InterfaceTable. USB Signal Interface USBHKADCHouse Keeping ADC Table. Hkadc channel tableKey Pad Table. Key Matrix Mapping Table21 Camera Socket Type Connector Camera InterfaceCAMDATAOUT3 Dvdd 22 Schematic of KEY back light circuit KEY side Keypad LightLCD Module NM176CN1 Tovis Display & LCD FPC InterfaceAudio Signal Processing & Interface 24 Audio Interface Detailed DiagramMSM6245MSM6245 Codec pins 25 Audio part schematicsMIC Audio part schematics Audio AMPAudio Mode Main Features LG-U250/KU250 Main featuresLogic Audio Bluetoot SW100 U101 U500 FL101 U100 FL104 U103 X100 Logic / Audio U301 S300Trouble Shooting RF ComponentUmts Signal Pathumts RF Signal Pathgsm RF Schematic of the VC-TCXO Block Checking VC-TCXO BlockTest Point of the VC-TCXO Block Check C312 of Pmic U300 Check R213 of MSM U201 Schematic of the Front-End Module Block Checking Front-End Module BlockTest Point of the Front-End Module Block Logic Table of the FEM For testing, Max power of UMT 2100 is needed Checking Umts BlockChecking Tx level Trouble Shooting Checking Umts PAM Control Block PAM control signal Checking RF Rx Level TP2 TP4Trouble Shooting Checking GSM Block Schematic of RF Tx level Checking RF Tx levelTrouble Shooting Checking PAM Block TP1 TP4 TP2TP3Checking RF Rx Block TP1. DCS RX InputTrouble Shooting Checking Bluetooth Block BluetoothSignals exits? Change the M100 Signals exits?Start Change the Main boardPower on Troubleshooting Vregmsmc Vregmsme Vregmsmp Charger Troubleshooting ChargerChange the board Charger Troubleshooting Flow Connection OK?Change TA Or USB Cable Q302 Q301Charging part Main PCB Front USB Troubleshooting Go to power on trouble shootingCable is inserted? Insert cable Q400 pin 4 is 5V? Check Q300 pinSIM Detect Troubleshooting Start Re-insert the SIM cardYes EndUsim Camera Troubleshooting StartYes Camera is OK? Yes Check the CammclkYes Change the Main board 103C350 C447 U501 U303C348 C349104 Keypad Backlight Troubleshooting Figure.Keypad backlight LED part 105Main LCD Troubleshooting 106Receiver Path 107108 Headset path 109110 Speaker phone path 111112 Main microphone 113114 Headset microphone 115116 Vibrator Work well? Yes End117 118 Downloading Procedure U250/KU250 DownloadIntroduction Connecting to PC 120Keep All Contents EraseEFS121 Choosing image files 122123 124 Downloading 125126 127 Tools 128Troubleshooting Download Errors 129130 NV Restore Error 131132 Port number 133U250/KU250 RF Functional Block Diagram 134 GSM & Umts RF BlockRF Block Component 135 Interface Diagram 1 RTR6275 & MSM6245 Interface DiagramRTR6275 & MSM6245 Interface Diagram 136 Memory Interface Diagram 137 Memory Interface3 USB,UART,SIM,JTAG Interface USB, UART, SIM, Jtag Interface 138Main RF signal Control signal 139Placement Top Side 140Bottom Side 141142 Circuit Diagram 143144 Nand & LCD145 EBI2WEN Nandready Nandale Nandcle Resoutn EBI2OENLCD Connector 146147 148 Configuration of HOT Kimchi Configuration of directory149 150 151 MSVCP60D.DLL MSVCRTD.DLLHow to use HOT Kimchi Procedure152 153 Test Program Setting 154Wcdma Test Mode 155GSM Test Mode 156Exploded View & Replacement Part List 157158 Replacement Parts Mechanic component 159160 Replacement Parts Main component 161162 163 164 165 166 167 DUPLEXER,IMT168 169 170 171 RES,ARRAY,R172 Vctcxo173 Accessory 174