1. 4.3.1 Power Circuit Diagram 4.3.1.1 Power-On Trouble +2.6V MSMP2 U503 4.3 Logic Part Trouble U502 +1.4V_ MSMC +2.6V_ MSMP2 +1.8V_ MSMP1 +2.9V_ RX0 +2.8V_ TCXO +2.9V_ RX1 +2.6V_ MSMA

2. Checking Flow START YES Check Battery Voltage > 3.4V ? NO Charge of Change Battery and try again Replace the U502 Re-download software & try again The power-on procedure is completed. The problem may be elsewhere. The Phone will power on. Replace the main board. Check the contact of power-key or dome switch Push power-on key and check the level change of U502 PWR_ON Check the voltage Level of the following port at U502 +1.4V_MSMC +2.6V_MSMP2 +1.8V_MSMP1 +2.6V_MSMA +2.8V_TCXO +2.9V_RX The logic level at PS_HOLD(R502) of U502 = High ? Does it work properly? YES NO YES

3. Circuit Diagram 4.3.1.2 Charging Trouble Test Points V_CHAR C605 VBATT(+VPWR) Q603Pin1 CON603 Q600 Q601 Q602

4. Checking Flow SETTING : Connect the battery and the charging adaptor (TA) to the phone START YES Voltage at +V_CHAR of Q601 = 5V? NO The charging adaptor (TA) is out of order. Change the charging adaptor. Replace Q600, Q601 Voltage at C605 = 5V? Voltage at +VPWR of Q603 = 4.2V? YES NO YES Replace Q603 The logic level at CHG_MODE of Q602 = Low? NO Replace Q602 Is the battery charged NO The battery may have the problem Change the battery and try again. Charging will operate properly YES

5. 4.3.2 LCD Circuit Diagram 4.3.2.1 LCD Trouble Test Points LCD Control signals From MSM : D2[0:15], MLCD_REST/, SLCD_RESET/, MLCD_CS/, SLCD_CS/, WE2/, RS F404 F406 F408 F409 F407 F403 F405 CON400 U502 +2.8V_LCD Check point - The assembly status of the LCD Module - The Soldering of connector

6. START Voltage at +2.8V_LCD of U502 = 2.8V? Check the Control signal D2[0:15], RESET/, LCD_CS/, WE2/,RS Change the LCD Module No Yes Replace U502 Check CON400 soldering Re-solder CON400 Yes Checking Flow ; Check F403, F404, F405, F406, F407, F408, F409

7. 4.3.3 Camera Circuit Diagram 4.3.3.1 Camera Trouble Camera Control signals From MSM : CAM_DATA[0:7], CAM_REST/, CAM_SDA, CAM_SCL, CAM_CLK_IN, CAM_PCLK

8. Test Points VR603 CON601 Check point - The assembly status of the Camera Module - The Soldering of connector U503 X400 L400 VR600 VR601 VR602 U505

9. START Check the clock to Camera at L400 (48MHz) Check the clock from Camera at VR602 : CAM_PCLK Check the Control signal CAM_DATA[0:7], CAM_RESET/, CAM_SDA, CAM_SCL Camera will work properly Replace X400 No Yes Replace the Camera module Check CON601 soldering Re-solder CON601 Yes Checking Flow ; Check VR600, VR601, VR602, VR603 Check the voltage of the following LDOs : +2.8V_CAM_AVDD +2.8V_CAM_VDD +1.8V_CAM_VDD No Replace U503/U505 Yes

10. 4.3.4 Audio Circuit Diagram 4.3.4.1 Speaker Trouble Test Points U301 C302 C301 L304L303L301L302

11. SETTING : “Melody on” at sounds of test menu. Voltage at L300 Is about 3.4~4.2V START Check the audio signal at C301, C302 Check the audio signal at L301~L304 Check the Soldering of U301 Check the state Of contact of speaker Speaker will work properly NO Yes Replace L300 Replace U301 Re-solder U301 Check the Soldering of C301, C302 NO Yes Replace MSM Re-solder C301, C302 Checking Flow NO Replace Speaker

12. 4.3.4.2 Receiver Trouble Circuit Diagram Test Points U301 C302 C301 L304L303L301L302 L306 L305

13. Voltage at L300 Is about 3.4~4.2V START Check the audio signal at C301, C302 Check the audio signal at L305, L306 Check the Soldering of U301 Check the state Of contact of receiver Receiver will work properly NO Yes Replace L300 Replace U301 Re-solder U301 Check the Soldering of C301, C302 NO Yes Replace MSM Re-solder C301, C302 Checking Flow NO Replace Receiver

14. 4.3.4.4 Headset Trouble Circuit Diagram Test Points U301 C302 C301 L304L303L301L302 L306 L305 C311 C309

15. Checking Flow START Does the audio Profile of the phone change to the headset mode? Can you hear your voice from the headset? The headset will work properly Insert the headset to the handset. Change the headset and try again. No Yes Set the audio part of the test equipment to echo mode Headset detect problem Can you hear your voice from the headset? Set the audio part of the test equipment to continuous wave mode Headset receiving Path problem Can you hear the sound from the headset? Headset sending path problem 1 4 2 3 No Yes No Headset receiving path problem 2 Level of C309, C311 is about 1.2V ? Check soldering of Pin2,3 of CON302 Change main board Download S/W Re-soldering of Pin2,3 of CON302 Yes No Yes

16. Headset detect problem Level of pin4 of CON302 Is 1.65~2.10V? Re-solder R315 No Yes 1 Check soldering R315 Check soldering Q300 Level of EAR_JACK_SENSE/ Is low? Re-solder Q300 Download SW 4 No Headset sending path problem Headset detect problem Headset sending path problem 3 Level of pin4 of CON302 Is 1.65~2.10V? Does it work? Re-solder R315 Download SW Does it work well? 4 Change main board No Yes No Yes

17. 4.3.4.3 Mic Trouble Circuit Diagram Test Points M200 R238

18. SETTING : After initialize 5515C, Test Cellular START Check the voltage level at R238 is 1.0~2.0V Check the soldering Of R238 Re-solder R238 Replace MSM Check the signal level at each side of MIC. Replace the microphone Check the soldering at C2001, C2002 Check the soldering of MIC NETWORK Re-solder MIC NETWORK MIC will work properly Checking Flow Yes No Yes Re-soldering C2001, C2002

19. 4.3.6 Vibrator, Mini SD Detect, and USB Interface Circuit Diagram 4.3.6.1 Vibrator Test Points R417 Q401 Q402 D400 R416 R418

20. Checking Flow SETTING : “Vibrator on” at Sounds of test menu START Is the voltage of MOTOR_EN about 2.6V ? Change the main board Check soldering of R416, R417, R418 Re-solder R416, R417, R418 Check the state at Contact of Vibrator Re-contact vibrator Replace Vibrator The vibrator will Work properly No Yes Is Q401, Q402 Working? Replace Q401, Q402 No Yes

21. Circuit Diagram 4.3.6.2 Micro SD Detect Test Points CON300 PIN 1 R503U502 PIN 2 PIN 3 PIN 4 PIN 5 PIN 7 PIN 8 PIN 9

22. Checking Flow START Level of SD_DETECT at PIN 9 of CON300 is ‘High’ ? Level of +3.0V_SD at U502 is 3.0V ? Levels of SD_CMD(PIN3 of CON300) and SD_DATA[0]~DATA[3](CON300) are ‘High’ ? THE MINI SD CARD WILL BE DETECTED Check the soldering of R327 & CON300 Replace U502 No Yes Frequency of SD_CLK(PIN5 of CON300) is about 9.6MHz ? Yes No SETTING : Insert the mini SD card into the phone Replace the MSM Access a file in the micro SD ; play music or view a PIX/FLIX Replace the main board

23. Circuit Diagram 4.3.6.3 USB Interface C538 R200 R538 U502 Test Points X200

24. Checking Flow START YES Level of VBUS at R538 is 5.0V ? NO Check the connecting of the data cable Check the voltage of the following port at U502 VIO=2.6V? VPU=3.3V? YES NO YES Check the soldering U502 Re-soldering U502 Replace U502 Replace the MSM Level of USB_SUPEND at C538 is ‘Low’ ? Check the voltage level at R537 Is it almost 3.3V? YES NO Check the soldering R537,R544,R545 Re-soldering R537,R544,R545 Replace U502 THE USB INTERFACE WILL WORK PROPERLY The Frequency at X200 is 48 MHz? YES NO Check the soldering X200,R200 Re-soldering X200,R200 Replace X200,R200 NO YES NO YES