Dead mobile check ing

 DEAD Mobile STEP BY STEP TESTING-

NOTE- 

👉 1- 5 MINUTES EYE TESTING COMPALSARY (PHYSICAL CONDITION, ANY SHORTING & COMPONENT DAMAGE).

👉 2- DEAD HANDSET TESTING WITHOUT BATTERY & CONNECT CHARGER COMPALSARY.

👉 STEP 1- CHECK BATTERY VOLTAGE (MINIMUM 3.7v) & BOOST BATTERY & CHECK NEW BATTERY.

👉 STEP 2- CHECK AMPERE TESTER (6-PORT) READING (WITH BATTERY).

👉 STEP 3- CHECK SHORTING IN BATTERY CONNECTER THROUGH MULTIMETER.

👉 STEP 4- CHECK SHORTING IN DC POWER SUPPLY.

👉 STEP 5- CHECK VBUS VOLTGE (5V) IN CHARGING CONNECTOR.

👉 STEP 6- CHECK VBUS VOLTGE (5V) IN SUB BOARD (BTB CONNECTOR) & MAIN BOARD (BTB CONNECTOR).

👉 STEP 7- CHECK VBUS VOLTGE (5V) INPUT 5v IN OVP IC & OUTPUT 5v IN OVP IC.

👉 STEP 8- CHECK VBUS VOLTGE (5V) INPUT 5v IN CHARGING IC PINS & CONNECTED COMPONENTS.

👉 STEP 9- CHECK VBUS VOLTGE (5V) INPUT 5v IN CHARGING IC VARIFICATION CAPACITOR (MID, PMID & USB-MID).

👉 STET 10- CHECK BOOT CAPACITOR (BTST, BOOT_STRAP, BOOT_PWR & BOOT_CAP) ONE SIDE 4v & SECOND SIDE 8v.

👉 STEP 11- CHECK CHARGING IC OUTPUT VPH VOLTAGE & SWITCHING COIL (3.7v TO 4.2v).

👉 STEP 12- CHECK CHARGING IC OUTPUT VBAT VOLTAGE (3.7v TO 4.2v).

👉 STEP 13- CHECK DC POWER SUPPLY READING.

👉 STEP 14- CHECK SHORTING THROUGH MULTIMETER (SECTION BY SECTION).

👉 STEP 15- CHECK VOLTAGE IN POWER KEY (1.8v TO 4.2v).

👉 STEP 16- CHECK BUCK COIL GR (GROUND RESISTANCE) & VOLTAGES IN NEAR POWER IC BIG BUCK COILS.

⭐ BUCK LINE VOLTAGES- (LOW LDO BUCK LINE- 1.3v, HIGH LDO BUCK LINE- 2.0v & OTHERS BUCK LINES 0.6v TO 1.2v).

⭐ NOTE- 1- LOW LDO BUCK LINE & HIGH LDO BUCK LINE RETURN TO POWER IC & OTHER BUCK LINES GO TO CPU).

⭐ 2- BUCK VOLTAGES STABLE MEANS CPU OK & BUCK VOLTAGES FLIKER MEANS CPU NOT OK), (SOLUTION CPU REBALL & CHANGE).

⭐3- MEDIATEK CPU HANDSET EXTERNAL BUCK LINE CHECKING IS COMPALSARY (VS1 & VS2). 

👉 STEP 17- CHECK 1.8v VOLTAGE IN FAULT_N LINE.

👉 STEP 18- CHECK CRYSTAL OSCILLATOR VOLTAGE (1.8v), REMOVE & PUT BACK, CHECK NEW CRYSTAL OSCILLATOR.

👉 STEP 19- CHECK BBCLK & SLPCLK VOLTAGES

⭐1- BASEBAND CLOCK VOLTAGE - 0.5v TO 1.8v (POWER IC TO CPU).

⭐2- SLEEP CLOCK VOLTAGE - 0.5v TO 1.8v (POWER IC TO CPU).

👉 STEP 20- CHECK 1.8v IN CHARGING & POWER IC TESTING POINT. 

⭐(QUALCOMM - PON_RESET, PM_PON_RESET_N, SYS_OK_PGOOD & WRST_N, MSM_RESOUT_N).

⭐(MEDIATEK - RESETB & SYSRSTB).

⭐(HISILICON - SOCT_RST_PMU_N & PMU_PERI_EN).

👉 STEP 21- CHECK 1.8v IN CPU TESTING POINT.

⭐(QUALCOMM - PS_HOLD, MSM_PS_HOLD & EDL POINT).

⭐(MEDIATEK - WATCHDOG & RCT32K_CK).

⭐(HISILICON - PWM_PWR_PSHOLD).

👉 STEP 22- CHECK COM-PORT IN COMPUTER SYSTEM DEVICE MANAGER (SHORT EDL, SHORT CLK RESISTOR TO GROUND) & CONNECT COMPUTER.

👉 STEP 23- CHECK CPU TO EMMC (EMCP & UFS) CONNECTING COMPONENTS (CLK LINE RESISTOR, CMD LINE RESISTOR, DATA LINE RESISTOR & RST RESISTOR).

👉 STEP 24- CHECK EMMC (EMCP & UFS) VOLTAGES NEAREST COMPONENTS (ISP & LDO LINE VOLTAGES- 1.2v, 1.8v, 2.8v).

⭐ BGA 221 - ROM VOLTAGES (VCCQ- 1.8v, VCC1- 2.9v), RAM VOLTAGES (VDD1- 1.8v, VDD2- 1.225v, VDDQ- 1.225v, VDDCA- 1.225v, RF- 0.6v).

⭐ BGA 254 - ROM VOLTAGES (VCCQ- 1.8v, VCC1- 2.9v), RAM VOLTAGES (VDD1- 1.8v, VDD2- 1.1v, VDDQ- 0.6v).

👉 STEP 25- CHECK DOWNGRADE FIRMWARE OR UPGRADE FIRMWARE.

👉 STEP 26- CHECK EMMC (EMCP & UFS) HEALTH IN UFI BOX, EASY JTAG & ANY PROFESSIONAL CHIP PROGRAMING BOX).

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Techlogicmobiles Pada October 05, 2024 TechlogicMobiles