All manuals and user guides at all-guides.com Table of Contents 1. Circuit diagram instruction ..................3 1.1 Main board explored view ................3 1.2 Detailed Description of Circuit Chart ............4 1.3 RF circuit ......................4 1.4 Base band circuit ..................... 5 1.5 Function circuit ....................
All manuals and user guides at all-guides.com 1.2 Detailed Description of Circuit Chart RF PA transceiver (U112) U114 transceiver U103 SIM card 1 Key pad SIM card 2 Camera BT/WIFI T-card 1.3 RF circuit This phone is designed on SC6820 platform. RF main chip integration SR1019, PA use RDA6163A, TCXO uses 26MHz crystal oscillator.
All manuals and user guides at all-guides.com power amplifier and duplex switch. The I/Q signal is inputted to be performed signal modulation as the modulation signal. The modulated TXIF signals restrain its third harmonic by harmonic suppression filter. The follow-up TXIF signal will be sent to a discriminator on the offset frequency phase lock loop (OPLL).
All manuals and user guides at all-guides.com Camera 2.Fault maintenance Note: The PCBA repairing is a very important work during the final production of cellular phones. The speed and quality of repairing decides the yield and production efficiency. The repair idea is very important for a good repairing technician. Make sure not to heat a board right away once a phone reaches at hand.
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All manuals and user guides at all-guides.com 3 Trouble shooting and flow chart 3.1 Unable to power on the handset Failure to power on Check battery mounted correctly & Re-mount battery or battery voltage >3.4V? replace battery Check if Keyboard backlight can be lighted Check if LCD is Pay attention to...
All manuals and user guides at all-guides.com 3.2 No ring tone No ringtone Check soldering of Solder speaker.OK? speaker Replace speaker and OK! Mark the test failed speaker Mark the Check the speaker circuit mainboard with no short ciruit or open analysis result circuit Replace new...
All manuals and user guides at all-guides.com 3.3 LCD display fault Abnormal LCD Display Check If the lcd is damaged Replace new LCD Check if the lcd connector is Solder the lcd connector soldered well Check If the LCD is mounted Re-mount the lcd inverse Replace the new mainboard...
All manuals and user guides at all-guides.com 3.4 Charging fault Failure to Charge Check charger or Replace new Replace new Charger charger Check battery is good or not Replace new battery Check charger connector for Solder charger connector soldering defect Check charging circuit of Mark the mainboard mainboard for fault...
All manuals and user guides at all-guides.com 3.5 Camera fault Failure to use camera Check camera for damage Replace new camera Check if camera is soldered or Solder camera connector assembled well or Re-assemble camera Mark the mainboard Check camera circuit for fault with analysis result Replace new mainboard...
All manuals and user guides at all-guides.com 3.6 Fail to identify SIM card Failure to identify SIM card Check if SIM card is inserted correctly Reinsert or change new According to insertion direction SIM card Check Solder or replace SIM SIM connector for soldering connector defect...
All manuals and user guides at all-guides.com 3.7 MIC fault Unable to record No sound in microphone Solder or replace new Check mic for soldering defect micphone Check if mic sound hole is Clean mic sound hole and jammed re-assemble mic Mark the mainboard with Check mic circuit for fault analysis result...
All manuals and user guides at all-guides.com 3.8 Keypad fault Keypad doesn’t work correctly Check : DOME is pasted and Paste the DOME or keymat is assembled correctly assemble keymat again Is there any dirty on keypad Clean keypad surface and surface? test Is sidekey soldered well?
All manuals and user guides at all-guides.com 3.9 Receiver fault No voice in receiver Is receiver ok ? Replace new receiver No broken wire Check receiver connector for Solder receiver connector soldering defect Check receiver circuit for any Mark the mainboard with fault analysis result Replace new mainboard...
All manuals and user guides at all-guides.com 3.10 Vibrate fault Vibrator fault or No vibration Is vibrator soldered well ? Solder vibrator or replace vibrator Check : Wire of vibrator Replace vibrator isn’t broken Check vibrator circuit Mark the mainboard with No short circuit or open circuit analysis result Replace new mainboard...
All manuals and user guides at all-guides.com 3.11 FM fault Failure to open FM or FM can’t scan any station Software version is correct Re-download software Earphone can be detected and Replace earphone audio output is ok Check FM circuit Mark the mainboard with No short circuit or open circuit analysis result...
All manuals and user guides at all-guides.com 3.12 Bluetooth fault Bluetooth can’t work Software version is correct Re-download software Is BT antenna assembled Re-assemble BT antenna correctly? Check BT circuit Mark the mainboard with No short circuit or open circuit analysis result Replace new mainboard...
All manuals and user guides at all-guides.com 3.14 No signal No RF signal Is RF antenna assembled correctly? Re-assemble BT anntena Is the phone set into Flying Return to Normal mode mode? Mark the mainboard with Check RF circuit for any fault analysis result Replace new mainboard...
All manuals and user guides at all-guides.com 3.15 Failure to identify T-flash card Failure to read T-flash card Is T-flash card inserted correctly? Re-insert T-flash card Check: the T-flash card is ok? Replace new card Clean socket or replace Check card socket is clean and socket no physical fault Mark the mainboard with...
All manuals and user guides at all-guides.com 3.16 Earphone fault Failure to use earphone Check: earphone is ok? Replace new earphone No damage Check earphone connector for Solder earphone connector soldering defect Is there any foreign matter in Clean or replace connector earphone connector? Check earphone circuit for any Mark the mainboard with...
All manuals and user guides at all-guides.com 3.17 Unable to use USB Uable to use USB Check : USB cable is ok, no pin of Replace new USB cable connector is broken Check if USB connector is Solder or replace USB solder ok, no short circuit connector Replace new mainboard...
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