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LG -MC820 Service Manual
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LG -MC820 Service Manual

LG -MC820 Service Manual

Single band cdma mobile phone
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CDMA MOBILE SUBSCRIBER UNIT
LG-MC820
SERVICE MANUAL
SINGLE BAND
CDMA MOBILE PHONE
1

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Summary of Contents for LG LG-MC820

  • Page 1 CDMA MOBILE SUBSCRIBER UNIT LG-MC820 SERVICE MANUAL SINGLE BAND CDMA MOBILE PHONE...
  • Page 2 LG-MC820 Table of Contents CHAPTER 1. Circuit Description 1. RF Transmit/Receive Part ......................3 2. Digital/Voice Processing Part ....................8 CHAPTER 2. Trouble Shooting CHAPTER 3. Safety CHAPTER 4. Appendix 1) Assembly and Disassembly Diagram 2) RF Block Diagram 3) Circuit Diagram...
  • Page 3 LG-MC820 CHAPTER 1. Circuit Description 1. RF Transmit/Receive Part 1.1 Overview The RF transmit/receive part employs the direct conversion architecture (ZIF, Zero Intermediate Frequency). The transmit/receive frequency is respectively 824~849MHz and 869~894MHz. The block diagram is shown in [Figure 1-1].
  • Page 4 LG-MC820 [Figure 1-1] Block Diagram Of MC820 1.2 Description of Receive Part Circuit 1.2.1 Duplexer (DP100) The duplexer consists of the receive part bandpass filter (BPF) and the transmit part bandpass filter (BPF) which have the function of separating transmit/receive signals in the full duplex system using the transmit/receive common antenna.
  • Page 5 LG-MC820 Parameter Gain Mode 0(G0) Gain Mode 1(G1) Gain Mode 2(G2) Gain Mode 3(G3) Unit Gain Noise Figure Input IP3 1.2.3 Rx RF SAW FILTER (F101) The main function of Rx RF SAW filter is to attenuate mobile phone spurious frequency, attenuate noise amplified by the LNA and suppress second harmonic originating in the LNA.
  • Page 6 LG-MC820 The RFT6122 baseband-to-RF Transmit Processor performs all Tx signal-processing functions required between digital baseband and the Power Amplifier Module (PAM). The baseband quadrature signals are upconverted to the Cellular frequency bands and amplified to provide signal drive capability to the PAM. The RFT6122 includes an mixer for up-converting analog baseband to RF, a programmable PLL for generating Tx and Rx LO frequency, cellular driver amplifier and Tx power control through an 85 dB VGA.
  • Page 7 LG-MC820 1.4 Description of Frequency Synthesizer Circuit 1.4.1 Voltage Controlled Temperature Compensation Crystal Oscillator (U101) The temperature range that can be compensated by VC-TCXO which is the reference frequency generator of a mobile station is -30~+80 ° C. VC-TCXO receives frequency tuning signals called TRK_LO_ADJ from MSM6025 as 0.5V~2.5V DC via R and C filters in order to generate the reference frequency of 19.20MHz and input it into the...
  • Page 8 LG-MC820 2. Digital/Voice Processing Part 2.1 Overview The digital/voice processing part processes the user's commands and processes all the digital and voice signal processing in order to operate in the phone. The digital/voice processing part is made up of a keypad/LCD, receptacle part, voice processing part, mobile station modem part, memory part, and power supply part.
  • Page 9 LG-MC820 2.3 Circuit Description 2.3.1 Keypad/LCD and Receptacle Part Once the keypad is pressed, the key signals are sent out to MSM6025 for processing. In addition, when the key is pressed, the keypad lights up through the use of 10 Blue LEDs and LCD backlights up through the use of 2 white LEDs.
  • Page 10 LG-MC820 2.3.2.1 Audio Processing Part MIC signals are inputted into the audio codec, and amplified with programmable gain, and converted into digital signals(PCM). Then, they are inputted into MSM6025. In addition, digital audio signals(PCM) outputted from MSM6025 are converted into analog signals after going through the audio codec.
  • Page 11 LG-MC820 [Figure 1-2] Block Diagram Of Power Management IC 2.3.5 Logic Part The Logic part consists of internal CPU of MSM6025, MCP, DSP. The MSM6025 receives TCXO (19.20MHz) clock signals from U101, and then controls the phone during the CDMA mode. The major components are as follows:...
  • Page 12 LG-MC820 The ARM7TDMI 32-bit microprocessor is used and CPU controls all the circuitry. Some of the features of the ARM microprocessor include a 3 stage pipelined RISC architecture, both 32-bit ARM and 16-bit THUMB instruction sets, a 32-bit address bus, and a 32-bit internal data bus. It has a high performance and low power consumption.
  • Page 13 LG-MC820 CHAPTER 2. Trouble Shooting...
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  • Page 48 2.3.11 UIM Detect Trouble SETTING : Insert UIM CON400, and power on. Test Points Circuit Diagram CON400 PIN 1 Figure 2-24 – UIM SOCKET PART Figure 2-24 – UIM SOCKET Checking Flow START Does the UIM Change the UIM. Our Phone Supports 3V? supports 3V UIM only Check the condition of...
  • Page 49 LG-MC820 CHAPTER 3. Safety ▣ IMPORTANT Read This Information Before Using Your Hand-Held Portable Cellular Telephone First introduction in 1984, the hand-held portable cellular telephone is one of the most exciting and innovative electronic products ever developed. With it you can stay in contact with your office, your home, emergency service, and others. For the safe and efficient operation of your phone, observe these guidelines.
  • Page 50 LG-MC820 position the antenna up and over your shoulder. Do not hold the antenna when the phone is “IN USE”. Holding the antenna affects call quality and may cause the phone to operated at a higher power level than needed.
  • Page 51 LG-MC820 ▣ Aircraft Turn your phone OFF before boarding any aircraft. Use it on the ground only with crew permission. Do not use it in the air. To prevent possible interference with aircraft systems, US Federal Aviation Administration (FAA) regulations require you to have permission from a crew member to use your phone while the plane is on the ground.
  • Page 52 LG-MC820 CHAPTER 4. Appendix...
  • Page 54 □ □ System Block Diagram U104 MSM6025 F100 U106 G : 28dB IL : 2.2~2.5dB RFT6122 SKY77162 UART1 B9003 Connectivity Quadrature PROCESSOR UART2 Upconverter Test/Debug /R-UIM DACs Tx: 824~ System U401 844MHz Status UART3 PM6610 Gain Ctl ctls DAC_REF ctls &...
  • Page 55 LG -YD820 Main B' D LG -MC820 Main B' D SAFY0122305 DCN Tx DCN Rx...
  • Page 56 LG -MC820 Main B' D SAFY0122305 DCN Tx DCN Rx Audio_Mic Audio_Earmic Audio_Receiver Voice&keytone Audio_Receiver/Speaker Voice&keytone Audio_Earphone...
  • Page 57 LG -MC820 Main B' D SAFY0122305...
  • Page 58 LG -MC820 Main B' D SAFY0122305 Audio_Receiver Voice&keytone Audio_Receiver/Speaker Voice&keytone...
  • Page 59 LG -MC820 Main B' D SAFY0122305...
  • Page 60 LG -MC820 Main B' D SAFY0122305 Audio_Mic Audio_Receiver Voice&keytone Audio_MP3 Audio_Earmic Audio_Earphone...
  • Page 61 CON403 2Pin Connector -Doesn't heard receiver U605 Dual-SPDT -Doesn't Work Ear Phone Mode CON301 41Pin Connector -Main LCD doesn’t displayed CON303 30Pin Connector -Dosen't work Key-buttern U201 U607 MSM6025 Audio Amp - No Power On - Doesn't Work Speaker Phone, - Sleep Time Decrease MP3 and Headphone mode X201...
  • Page 62 CON601 EAR-MIC Jack -Doesn’t work Ear-Mic CON500 Camera socket - Doesn't work Camera U100 RF Cable Connector -No service -Low sensitivity CON702 Side-Key connector - Side key buttern dosen't work DP100 DCN Duplexer - No Service - No Make Call U108 HDET - Low TX Power...
  • Page 63 LED701,LED702,LED703, LED704,LED705,LED706, LED707,LED708,LED709, LED710 Blue LED - No Keypad Backlight...
  • Page 66 LG-MC820 Component List 1. Accessory Design No. LG Part No. Description Q’ty Remark ACGA0013201 COVER ASSY,BATTERY MHBY0000407 HANDSTRAP MMBB0168801 MANUAL,OPERATION SBPL0078701 BATTERY PACK,LI-ION SGEY0003301 EAR PHONE/EAR MIKE SET SSAD0018901 ADAPTOR,AC-DC EUSY0218203 MCEZ0001201 CASE ENSY0013101 CONN,SOCKET 2. Board Design No. LG Part No.
  • Page 67 LG-MC820 3. Mechanical Part Design No. LG Part No. Description Q’ty Remark MWAC0054101 WINDOW, LCD MDAG0012301 DECO, FRONT(LEFT) MCCC0025001 CAP,EARPHONE JACK MDAE0030301 DECO,FOLDER(UPPER) MTAA0089501 TAPE,DECO(UPPER) MTAA0089401 TAPE,DECO(LEFT) MTAA0089301 TAPE,DECO(RIGHT) MDAG0013501 DECO,FRONT(RIGHT) MCJK0041301 COVER, FRONT MTAA0089601 TAPE,DECO(LOWER) MDAF0007501 DECO,FOLDER(LOWER) MCCE0020101 CAP,RECEPTACLE...
  • Page 68 LG-MC820 MFBC0016301 FILTER, SPEAKER MPBM0010001 PAD, RECEIVER MTAB0085701 TAPE,PROTECTION MCCZ0014601 CAP( MIC) SPEY0031101 PCB, KEYPAD MTAB0085301 TAPE,PROTECTION(CAMERA) MSDC0010101 SPRING, LOCKER MSAZ0027001 SHEET(MSM) MTAZ0079701 TAPE(LCD) MGAB0009801 GASKET,EMI SURY0010301 RECEIVER MCCZ0014201 CAP, FLASH SJMY0007004 VIBRATOR,MOTOR MCCH0060701 CAP, SCREW MLAB0000701 LABEL, A/S MLAN0000602...
  • Page 69 LG-MC820 4. Main PCB 4-1 Main PCB Top Design No. LG Part No. Description Q’ty Remark L201,L202,L301,L302,L401, SFBH0000903 BEAD-INDUCTOR L402,L405,L501,L503,L604 L603 SFBH0001503 BEAD-INDUCTOR C630 ECZH0000818 CHIP-CAPACITOR C234,C235 ECZH0000826 CHIP-CAPACITOR C381 ECZH0000838 CHIP-CAPACITOR C218,C450,C472,C640 ECZH0000813 CHIP-CAPACITOR C301,C375,C376,C377 ECZH0001121 CHIP-CAPACITOR C620,C634 ECZH0001109...
  • Page 70 LG-MC820 R434 ERHZ0000443 RESISTOR R207 ERHY0003601 RESISTOR R500,R501,R502 ERHZ0000485 RESISTOR R428,R429 ERHZ0000203 RESISTOR R609,R616,R617 ERHZ0000405 RESISTOR R324 ERHZ0000438 RESISTOR R383,R620 ERHZ0000444 RESISTOR R218 ERHZ0000281 RESISTOR R737,R738 ERHZ0000486 RESISTOR R217 ERHZ0000204 RESISTOR R216 ERHZ0000204 RESISTOR R522 ERHZ0000406 RESISTOR R431,R432 ERHZ0000231 RESISTOR...
  • Page 71 EUSY0077401 SPDT VR301,VR302,VR303,VR304,VR30 SEVY0005801 EMI-FILTER X200 EXRY0001201 RESONATOR X201 EXXY0004601 RESONATOR X501 EXRY0001601 RESONATOR 4-2 Main PCB Bottom Design No. LG Part No. Description Q’ty Remark L104,L404,L406,L407,L408, SFBH0000903 BEAD-INDUCTOR L409,L502 MULTILAYER L115,L116,L118 ELCH0004708 -CHIP-INDUCTOR MULTILAYER L105 ELCH0004724 -CHIP-INDUCTOR L106 ELCH0004701...
  • Page 72 LG-MC820 C174,C175,C414,C506 ECZH0001114 CHIP-CAPACITOR C114,C176 ECZH0001123 CHIP-CAPACITOR C156,C382,C384 ECZH0001121 CHIP-CAPACITOR C118,C119,C122,C167,C351 ECZH0001109 CHIP-CAPACITOR C116,C169 ECZH0001115 CHIP-CAPACITOR C168 ECZH0001104 CHIP-CAPACITOR C157 ECZH0001107 CHIP-CAPACITOR C103,C111,C113,C158,C160, C181,C345,C404,C406,C479, ECZH0001101 CHIP-CAPACITOR C628 C170 ECCH0002003 CHIP-CAPACITOR C127 ECCH0002002 CHIP-CAPACITOR C102,C124,C132,C133,C134, C135,C138,C141,C143,C144, ECCH0002001 CHIP-CAPACITOR C145,C146,C147,C161,C163, C164,C520,C528,C529 C481...
  • Page 73 LG-MC820 R119 ERHZ0000510 RESISTOR R135,R136,R137,R138,R140, ERHZ0000404 RESISTOR R421 R117 ERHZ0000211 RESISTOR R474 ERHZ0000529 RESISTOR R105 ERHZ0000459 RESISTOR R373 ERHZ0000485 RESISTOR R444 ERHZ0000530 RESISTOR R127 ERHZ0003202 RESISTOR R141 ERHZ0000346 RESISTOR R109,R301,R350,R435,R507, ERHZ0000405 RESISTOR R513,R514,R515,R516,R526 R129 ERHZ0000203 RESISTOR R124 ERHZ0000351 RESISTOR R349,R475,R730...
  • Page 74 LG-MC820 F100 SFSY0018101 SAW-FILTER F101 SFSY0018201 RX_SAW_FILTER L403 ELCP0008001 POWER-INDUCTOR LED500 EDLM0005701 Q100,Q413 EQBA0000601 TRANSISTOR Q304,Q410,Q601 EQBN0012301 Q305,Q307,Q308,Q401 EQBN0012401 NPN-TR Q306 EQFP0005901 P-CHANNEL-FET Q309,Q502,Q602 EQBP0006701 PNP-TR Q409 EQBP0004102 PNP-TRANSISTOR Q415 EQFP0001301 P-CHANNEL-MOSFET U100 ENWY0003301 MOBILE-S/W U101 EXSK0005001 VCTCXO U102 EQFP0003501...
  • Page 75 LG-MC820 5. Key PCB 5.1 Key PCB TOP Design No. LG Part No. Description Q’ty Remark R701,R702,R703,R704,R705, ERHZ0000464 RESISTOR R706,R708,R709,R710,R711 LED701,LED702,LED703,LED704, LED705,LED706,LED707,LED708, EDLH0004501 LED709,LED710 5.2 Key PCB BOTTOM Design No. LG Part No. Description Q’ty Remark R707,R714,R715,R716 ERHZ0000484 RESISTOR R700,R713...