Monday, March 28, 2016

How to troubleshoot - Samsung galaxy tablet - GSM TELEPHONE GT-P7320 – power problem – touch problem – speaker problem – Charging trouble – Tablets repair and service

Category: Tablet Repair and Service 

Contents of this article 

  • Power ON problem 
  • Charging failure  
  • Touch pad not working 

Samsung galaxy GT-P7320

TROUBLESHOOTING 
Power On does not work
C1009 = 3.5V > 4.2V ?
Check CON1000 component and replace.
When Power key press, is R1500 is 0V ?
Check Power Key FPCB Part & C1519
MSM_PS_HOLD(R728) = 1.8V
After Check UCP400 circuit, Replace UCP400
Check U702 Power stage C794,C795 = 1.1V C787 = 1.8V, C776 = 1.8V,
After Check U702 circuit, Replace U702
Check U700 Power stage C740, C741 = 1.2V, C726 = 2.85V
After check U700 circuit, Replace U700
Check U1107 Power stage C1120 = 5V L1102 = 14~18V
After check U1107 circuit, Replace U1107
CP Power on does not work
Check the Setting-About device Baseband version
After SW D/L, recheck the Baseband version & if the reproducing, PBA is change.
Check U802 power stage C837 = 1.1V, C838 = 1.3V, C839 = 1.8V, C831 = 1.8V C832 = 2.85V
Check the U701 circuit & Replace U701
MDM _PS_HOLD = 1.8V
Check the R815,U806 circuit & replace U806
Check U600 power stage C607 = 1.1V
Check the U600 circuit & replace U600
Check the UCP600 state
Initial Failure
MDM_PON_RESET_N(C862), TP_MDM_PM_INT_N >= 1.8V(HIGH)
Check UCP400 (short, crack, etc.)
MDM2AP_WAKEUP(TP_M400), >= 1.8V(HIGH)
Check UCP600 (short, crack, etc.)
There is 32.768KHz wave forms at OSC701(C748) and OSC800(C835)
Replace OSC701 and OSC800
There is 32.768KHz wave forms at OSC701(C748) and OSC800(C835)
Replace OSC701 and OSC800
There are 19.2MHz wave forms at OSC700(C745) and 19.2MHz wave forms at OSC1100(C1104)
Replace OSC700 and OSC1100
LCD display OK?
Check the LCD part(short, crack, etc.)
Sound is OK?
Check the Audio Part(short, crack, etc.)
Insert SIM card
Check connection of HDC1001
re-connect and check again or change SIMsocket FPCB
Check the SIM Voltage. (R1033) >= 2.8
Change to the new SIM card. If it doesn`t still work SIM card after changing the SIM card, Check the UCP600 (Crack etc)
Abnormal charging
Check C1019 whether voltage is greater than 5V.
Check the TA and the DLC. (TA or DLC may not be connected properly)
Check C1101 whether the voltage reading is greater than 5V. C1011
Check U1003 chip
Check C851 whether voltage reading is greater than 4.2V
Check U803 chip (U803 chip may not work at room temperature)
Check C851 whether voltage reading is greater than 4.2V
Check U803 chip (U805 chip may not work) U805
Check C842 whether voltage is change when TA is connected
Check U803 chip (U803 chip may not work)
Microphone Part
Check main microphone function in cam recording mode
Check the status of MIC module
Replace MIC module
Check the HDC900 is connected
Connect the HDC900
L902 = 1.5V, L903 = 0.3V ? and check the soldering status
Check the U906 LDO and MIC. If there is crack, replace them
Speaker
Check speaker function. Play MP3 with maximum volume level.
Check the speaker module is soldered well.
Resolder speaker module
Check the L906,907,908,909 Signal when music is playing.
Check the U403 and near parts If there is crack, replace them
Check the C951, C954 Audio signal when music is playing
Check the U202 and near parts If there is crack, replace them
LCD
LCD is still off after PWR ON
Check the connection of HDC1100
Reconnect the HDC1100
Check the C1121 and High(about 18V)
Check the Backlight Driver IC(U1107)
Check C1110=1.8V, C1106=1.2V,C1108=3.3V
Check the PMIC(U702) DC-DC(U1100) BUCK(U1105)
Check the signal IDISPLAY_PCLK(TP1107) LCD_F(0)(TP1100)
Check the freq of C1105(19.2MHz)
Replace or resolder OSC1100
Replace LCD Module
Check the U1103
Touch Screen does not work
Check TSP Connector on Main PBA
Reconnect the SLC1200
Pin1 = 2.8 U1202 V(C1201)
Resolder or Replace U1202
U1200,1201 Pin J6 > 2.5V (C1204, C1208)
Resolder or Replace U1200,1201
U1200,1201 Pin J6 > 2.5V (C1204, C1208)
Resolder or Replace U1200,1201
Check the I2C signal of Sensor IC(R1200, R1201)
Resolder R1200, R1201
Replace TSP Module