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LG -YD636 Service Manual
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LG -YD636 Service Manual

LG -YD636 Service Manual

Single band cdma mobile phone
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CDMA MOBILE SUBSCRIBER UNIT
LG-YD636
SERVICE MANUAL
SINGLE BAND
CDMA MOBILE PHONE

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Summary of Contents for LG LG-YD636

  • Page 1 CDMA MOBILE SUBSCRIBER UNIT LG-YD636 SERVICE MANUAL SINGLE BAND CDMA MOBILE PHONE...

  • Page 2: Table Of Contents

    Table of Contents CHAPTER 1. NAM Input Method (Inputting of telephone numbers included) 1. Telephone Number and NAM Programming Method CHAPTER 2. Circuit Description 1. RF Transmit/Receive Part 2. Digital/Voice Processing Part CHAPTER 3. Trouble Shooting CHAPTER 4. Safety...

  • Page 3: Chapter 1. Nam Input Method (Inputting Of Telephone Numbers Included)

    CHAPTER 1. NAM Input Method (Inputting of telephone numbers included) 1. HOW TO POWER UP ENTER PIN ENTER PIN CHV PIN Avail Cnt: 03 Avail Cnt: 03 Verified [**** 1. When you press power key, “Enter PIN Avail cnt:03” message is displayed. 2.
  • Page 4 • Nam Name is displayed , then press [OK]. • ACCOLC is displayed, then press[OK]. • Now, the basic programming is completed. To reset the handset, press [ Done]. The detail programming method is same as basic programming. Set up required values and then, press the Up-Down key in an effort to move to the next screen..

  • Page 5: Chapter 2. Circuit Description

    LNA and mixer, attenuate receiver spurious response and suppress local oscillator energy. As a result frequency sensitivity and selectivity of mobile phone increase. The specification of LG-YD636 duplexer described below ; Tx to Rx (min)
  • Page 6 Noise Amplifier (LNA) are low noise figure, high gain, high intercept point and high reverse isolation. The frequency selectivity characteristic of mobile phone is mostly determined by LNA. The specification of LG-YD636 LNA is described below: Parameter Gain mode 0 Gain mode 1...
  • Page 7 1.3 Transmit Part Circuit Description 1.3.1 RFT6122 The RFT6122 baseband-to-RF Transmit Processor performs all Tx signal-processing functions required between digital baseband and the Power Amplifier Modulator (PAM). The baseband quadrature signals are upconverted to the Cellular frequency bands and amplified to provide signal drive capability to the PAM.

  • Page 8: Digital/Voice Processing Part

    1.4 Description of Frequency Synthesizer Circuit 1.4.1 Voltage Control Temperature Compensation Crystal Oscillator The temperature range that can be compensated by VC-TCXO which is the reference frequency generator of a mobile station is -30~+80 C. The VC-TCXO receives frequency tuning signals called TRK_LO_ADJ from MSM as 0.5V~2.5V DC via R and C filters in order to generate the reference frequency of 19.2MHz and input it into the frequency synthesizer of UHF band.
  • Page 9 2.2.3 MSM6025 (Mobile Station Modem) Part MSM is the core elements of CDMA terminal and carries out the functions of CPU, encoder, interleaver, deinterleaver, Viterbi decoder, Mod/Demod, and vocoder. 2.2.4 Memory Part The memory part is made up of a flash memory, SDRAM for storing data. 2.2.5 Power Supply Part The PMIC(PM6610) is made up of 7 Regulators and direct connet to Batt.
  • Page 10 processor, digital FM (DFM) processor, QCT’s latest generation of DSP, the QDSP4000™ core, for voice compression and applications support, PLL and an ARM® ARM7TDMI microprocessor. Also integrated in the MSM6025 device are analog functions such as a wideband mono codec and analog interfaces for the radioOne RF ASICs.
  • Page 11 LDO(in PMIC) for +2.60V_TX part is enabled on traffic state, and gives the power TX part devices. LDO(in PMIC) for +2.60V_RX part is enabled on idel state, and gives the power RX part devices. Turn OFF When the PWR key is pressed during a few seconds, PMIC is turned on by PWR_ON_SW/ and then, 'Low' is outputted on PS_HOLD.
  • Page 12 CHAPTER 3. Trouble Shooting CHAPTER34. Trouble Shooting 3.1 Rx Part Trouble 3.1.1 When Tx power isn’t enough Test Point Checking Flow START Rx TEST SETUP(HHP) - Test Channel : 610 E5515C Setup - CH : 610 - Sector Power : -30 dBm Spectrum Analyzer Settiing Oscilloscope Setting 1.
  • Page 13 3.1.2 Checking Regulator Circuit Test Point U401. 29 (+2.6V_Rx) U401. 7 High Circuit Diagram Checking Flow +2.6V_Rx OK? Pin 7. High? Changing Board Check Pin 29 of U401 Check Pin 7 PMIC Circuit is OK See Replace U401 of U401 next Page to check VCTCXO...
  • Page 14 3.1.3 Checking VCTCXO Circuit Test Point Checking Flow Check U101 Pin 3 ◆ Refer to Graph 3-1(a) U101. 4 VCTCXO Circuit is Ok 19.2MHz OK? See next Page to check Duplexer Check U101 Pin 4 ◆ Refer to Graph -1(b) +2.85V OK? Changing U101 U101.
  • Page 15 3.1.4 Checking Control Signal Test Point U107. 3 (SBDT) U107. 4 (SBCK) U107. 5 (SBST) Checking Flow Check Pin 3, 4, 5 Download the SW Level is High? ◆ Refer to Graph 3-2(a,b) Check SBDT, SBCK SBST Check if there is Similar? Download the SW Any Major Difference...
  • Page 16 3.1.5 Checking Duplexer & Mobile SW Test Point U100. 1 DP100. 8 DP100. 5 Circuit Diagram...
  • Page 17 3.1.6 Checking Mobile SW & Duplexer Checking Flow Rx TEST SETUP(HHP) - Test Channel : 610 E5515C Setup - CH : 610 - Sector Power : -30 dBm Spectrum Analyzer Settiing Oscilloscope Setting Check U100 Pin 1 Check if there is Detected Signal? Changing U100 Any Major Difference...
  • Page 18 DP100 Pin 8 Graph 3-3(b) DP100 Pin 5 Graph 3-3(c)
  • Page 19 3.1.7 Checking Rx I/Q data Test Point R138 (Rx_Q_P) R137 (Rx_Q_N) R136 (Rx_I_N) R135 (Rx_I_P) Waveform R135 (Rx_I_P) R136 (Rx_I_N) R138 (Rx_Q_P) R137 (Rx_Q_N) Graph 3-4(a) Graph 3-4(b) Checking Flow Check R138, R137, R136, R135 Replace U107 Similar? Check if there is Any Major Difference ◆...
  • Page 20 3.2 Tx Trouble Test Point DUPLEXER VCTCXO Mobile SW RFT6122 Checking Flow START √ Press “******159753“ in Phone idle state √ Press right key insert FCC Mode -Set CH400 & AGC 400 √ Spectrum analyzer setting √ Oscilloscope setting 1. Check Regulator Circuit 4.
  • Page 21 3.2.1 Check Regulator Circuit TEST POINT U401 Pin29 U201 TP214 TX ON V_RFTX 2.6V Circuit Diagram MSM6025 Checking Flow U401 U201 VREG_RFTX TP214 Check Pin29 Replace U201 2.6V OK? TX ON High? Regulator Circuit is OK Replace U401 See Next Page to Check VCTCXO...
  • Page 22 3.2.2 Check VCTCXO Circuit TEST POINT Checking Flow U101 Pin 3 VCTCXO Circuit is OK 19.2MHz OK? See next page to check SBI control signal U101 Pin3 VCTCXO OUT Pin4 Replace U101 2.85V OK? U101 Pin4 Check U401 2.85V_TCXO Circuit Diagram Waveform U101 Pin4 2.85V_TCXO U101 Pin3 VCTCXO_OUT...
  • Page 23 3.2.3 Check SBI Control Signal Test Point U106 RFT6122 TP202 SBST Circuit Flow Download the SW Check TP202 Level is appear? Similar? Download the SW Control Signal is OK See next page to check RFT6122 Circuit Waveform SBDT SBST SBCK SBCK...
  • Page 24 3.2.4 Check RFT6122 Circuit Test Point Circuit Flow Check U201 Check C174,C175 I,Q Level is Appear? U106 Pin23 CELL_OUT Check U106 Pin12 Level (near 1V) is Appear? Replace U106 C174,C175 I Q DATA Output signal Check U106 Pin23 Replace U106 U106 Pin12 (837MHz) is Appear? TX_CP...
  • Page 25 3.2.5 Check PAM Circuit Test Point U100 Pin4 U104 Pin12 Vreg 2.85V RF_OUT U104 Pin9,10,11 Vcc2 U104 Pin2 Vreg 2.85V U104 Pin5 Vcc1 U102 Pin3 U104 Pin4 Vout RF_IN Circuit Diagram...
  • Page 26 Circuit Flow Check F100 Check U104 Pin4 Input Level is Appear? Check U104 Pin2 Vreg 2.6~2.8V OK? Check Q100,U401 Level is Check U102 Pin3 Check U102 3.3V~4.2V OK? Level is Check U104 Pin5,9,10,11 Replace U104 3.3V~4.2V OK? Output Level Check U104 Pin12 Replace U104 is Appear? PAM Circuit is OK...
  • Page 27 3.2.6 Check Duplexer & Mobile SW TEST POINT U100 Pin2 ANT_OUT DP100 Pin8 TX->ANT Circuit Flow Replace DP100 Check DP100 Pin8 Level is Appear? Level is Appear? Check U100 Pin2 Replace U100 Redownload SW and Recalibration Circuit Diagram...
  • Page 28 3.3 Logic Part Trouble < PM6610 FUNCTIONAL BLOCK DIAGRAM3.3 >...
  • Page 29 3.3.1 Power On Trouble Circuit Diagram Test Point +2.6V_RX+2.6V_TX +2.85V_TCXO U401 PM6610 +2.6V_MSMA +2.85V_MSMP +2.85V_RUIM 1.9V_MSMC PM6610 POWER MANAGEMENT SECTION...
  • Page 30 Checking Flow START Check Battery Voltage Charge of Change Battery and try again > 3.45V ? Push power-on key and check Check the contact of power-key the level change of or dome switch U401 PWR_ON_SW/ Check the voltage of the following port at U401 +2.6V_MSMA +2.85V_RUIM Replace U401...
  • Page 31 3.3.2 Charging Trouble Test Points R415 Q401 C410 R438 R411 PM6610 CHARGER CIRCUIT PART Block & Circuit Diagram R411 C410 R438 Q401 OΩ R415 PM6610 CHARGING CONTROL BLOCK...
  • Page 32 Checking Flow SETTING : Connect the battery and the charging adaptor (TA) to the phone START The charging adaptor (TA) is out of order. Voltage at V_CHG Change the charging adaptor. of U401 = 5.15V? Q401,R415,R438,R411 Re-soldering Q401,R415,R438,R411 well-soldered? Voltage across Replace R415 R415 is ~100mV.
  • Page 33 3.3.3 Receiver Trouble Test Points C370 CON403 R301 R300 EAR10- EAR10+ RECEIVER CONNECTOR PART Circuit Diagram Block Diagram RECEIVER PART RECEIVER CODEC BLOCK...
  • Page 34 Checking Flow START Check the signal level of Check the soldering Replace the Main board. EAR10+,EAR10- at R300,R301. R300,R301 MSM6025 is out of order. Are these levels about 1.2V? Re-soldering R300,R301 Replace the Receiver Check the contact state of Receiver connector The Receiver will work properly Waveform...
  • Page 35 3.3.4 USB Interface Trouble Test Points R311 C310 C309 X200 Q300 C306 C308 U301 R320 DP1681 C307 L301 R318 C311 R201 R376 C312 C313 USB RESONATOR USB TRANCEIVER PART Block Diagram Connecting MSM6025 to Five-Wire Interface Transceiver...
  • Page 36 Circuit Diagram USB TRANSCEIVER USB RESONATOR...
  • Page 37 Waveform USB Interface waveform...
  • Page 38 Checking Flow START Check Voltage at VBUS Check the contact state of Data-cable of U301 = 5.0V ? Check the voltage of the following Re-soldering Check the soldering U301, L301 port at U301 U301,L301 VIO=2.85V? VPU=3.3V? Replace U301,L301 X200 is working? Re-soldering Check the soldering X200,R201 Oscillator frequency = 48 MHz?
  • Page 39 3.3.5 Speaker Trouble Test points R457 C425 C447 R455 R430 CON300 U402 R426 SPK PHONE AUDIO AMP PART SPK CONNECTOR PART Circuit Diagram SPK PHONE AUDIO AMP...
  • Page 40 Checking Flow SETTING : “Melody on” at sounds of test menu. START Change Main Board Voltage across C447 Check the soldering of PIN Internal Pattern is Is over 3.4~4.2V 6 of U402 opened Re-soldering Pin 6 of U402 Check the signal level of Check the soldering Replace MSM PIN4 of U402...
  • Page 41 3.3.6 MIC Trouble Test points C455 R434 C456 MIC FILTER PART MIC & MIC BIAS PART Circuit Diagram MIC FILTER...
  • Page 42 Checking Flow SETTING : After initialize 5515C, Test Cellular START Check the soldering Voltage across Re-solder R434 Of R434 Replace MSM Check the signal level Replace the microphone At each side of MIC. Is It a few tens mVAS? Check the soldering of Re-solder C455, C456 C455, C456 Check the soldering of...
  • Page 43 3.3.7 Vibrator Troble Checking Flow R437 U401 CON402 PM6610 PART MOTOR CONNECTOR PART Block & Circuit Diagra MOTER_EN\ MOTOR PM6610 VIBRATION CONTROL BLOCK...
  • Page 44 Checking Flow SETTING : “Vibrator on” at Sounds of test menu START Check the soldering Is the voltage at pin 10 Re-solder pin10 of U401 Of pin10 at U401 Of U401 near OV? Replace U401 Check the soldering of Re-solder R437 R437 Check the state at Re-contact vibrator...
  • Page 45 3.3.8 Key Backlight LED Trouble Test Points LED409 LED408 LED403 LED407 LED402 LED406 LED401 LED405 LED400 LED404 KEYPAD & INDICATOR LIGHT PART Circuit Diagram KEYPAD & INDICATOR LIGHT...
  • Page 46 Checking Flow START Is the voltage level VBAT Charge battery 3.6-4.2V? Are all LEDs LED400~409 Check the soldering of each R or replace LEDs not working working? Q400, Q402 is working? Check the condition of Q400, 402. If problem, Change Q400, 402 BACKLIGHT WILL WORK PROPERLY...
  • Page 47 3.3.9 UIM Detect Trouble SETTING : Insert UIM CON400, and power on. Test Points Circuit Diagram CON400 PIN 1 UIM SOCKET PART UIM SOCKET Checking Flow START Does the UIM Change the UIM. Our Phone Supports 3V? supports 3V UIM only Check the condition of Resolder or replace CON400 CON400 Good?
  • Page 48 3.3.10 Earphone Trouble Test Points Q401 PIN 3 U402 CON401 C460 PIN 4 Q408 C443 R450 Q409 EAR MIC JACK & RADIO PART EAR MIC JACK & RADIO Circuit Diagram...
  • Page 49 Checking Flow START Insert the earphone to the handset. Earphone detect problem Does the audio Profile of the phone change to the earphone mode? Audio path problem Set the audio part of the test equipment to echo mode Set the audio part of the test equipment to Earphone receiving continuous wave mode...
  • Page 50 Earphone detect problem Earphone detect problem Level of pin4 of CON401 Level of R207, R208 about 2.6V? about 2.6V? Re-solder R207, R208 Check soldering Re-solder Q408 Q408 Check working Replace Q408 Q408 Earphone sending path problem Earphone sending path problem Re-download Level pin4 of CON401 Re-solder...
  • Page 51 3.3.11 LCD Trouble • LCD Control signals From MSM : D(0:15), LCD_RESET1/, A[1], LCD_CS/, LWR/ • Check point - The assembly status of the LCD Module - The Soldering of connector L300 Test Points CON301 LCD CONNECTOR PART Circuit Diagram LCD CONNECTOR...
  • Page 52 START Does LCD work properly? Change the LCD Module Check power 2.5V Check soldering L300 Re-soldering L300 Replace L300 Check the Control signal D[0:15], LCD_RESET1/, A[1], LCD_CS/, LWR/ Check CON301 soldering Re-solder CON301 LCD display will work properly...
  • Page 53 CHAPTER 4. 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 54 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. ▣ Antenna Care and Replacement Do not use the phone with a damaged antenna.
  • Page 55 ▣ 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.