How To Solve iPhone X Voltage Jumping Issue

Today, We getting the iPhone X main board to test, we observe the current value repeatedly jumps between 0mA and 50mA on DC power supply, and it is different from the normal booting current. Next, test whether the power supply of every circuit is normal. PP_VDD_MAIN is measured 4.2V; PP_VDD_BOOST measured is 4.2V. PP1V8-ALWAYS is 1.8V, all the values are normal. But when testing PP1V1_S2, PP0V8_SOC_FIXED_S1, PP1V8_S2 and other circuit voltage that output by power chip U2700 voltage are jumping constantly. According to previous experience, voltage jump is usually caused by a power supply circuit of U2700 output. Measured with digital multimeter, there is no short circuit was found for the dipole value of all power supply to ground.

We repaired iPhone 7P before and know that if crystal oscillator is false welding can also cause voltage jumping, And if iPhone CPU power supply is abnormal also can cause voltage jumping. Check the crystal oscillator we find no problem, then check the CPU power supply! As shown in iPhone schemtic diagram 14-3-1 and 14-3-2, there are three ways of power supply, not only directly into the CPU, but also through the small resistance or inductance into the CPU, the three voltage are PP1V2_SOC, PP0V8_SOC_FIXED_S1, PP1V8_IO. 

14-3-1

14-3-2

Testing the 3 power supply one by one, when the FL1092 inductor of PP1V8_IO is measured, one end is 1.8V while the other end is 0V.

14-3-3

Testing the end without voltage to the ground dipole value is 490, the normal is about 280. Then testing the inductor's noumenon value is very large, indicating the iPhone X inductor is damaged, so we replace a new inductor, the fault is repaired well.

Later, it was analyzed that the PP1V8_IO was renamed as PP1V8_XTAL after inductance FL1092, which was supplied to the CPU crystal module. It also verified that the voltage jump of iPhone X and the voltage jump of 7P before were actually the same thing. Hope this iPhone X repair case will help you.



TIPS: If you need professional cell phone repair tools to solve your trouble, please consult Here!

Comments

Post a Comment

Popular posts from this blog

2021 Latest MagicAWRT Adapter Restore Tool for Apple Watch

Image
 Here we have the latest MagicAWRT adapter Apple Watch restore tool in 2021, and MagicAWRT offers its complete solutions to fix many apple watch problems. MagicAWRT Adapter is intended for solving service problems with Apple Watch S0/SE/S1/S2/S3/S4/S5/S6 (38 mm / 42 mm / 40 mm / 44 mm). It can solve problems such as white apples, exclamation points, restarts, stuck on screens, poor touch, ID lock, etc. It also can fix related issues that are caused by  Apple Watch glass digitizer touch replacement. Apple Watch Firmware for MagicAWRT Adapter Restore Tool will not be provided, and the customer needs to download themselves. 1. Using MagicAWRT Adapter to reset Apple Watch Data with or without Backup MagicAWRT Recovery Adapter Restore Tool is the best iOS data restore software in the market because of its ease of use and attractive user interface. Most Apple Watch users data losses are due to accidents, failed jailbreaks, hardware and software failures, factory resets, and theft. It would
Read more

My iPhone Got Wet! How To Fix iPhone Water Damage?

Image
 Water damage tends to worsen with time, and it is among the more challenging DIY repairs to undertake, so this guide covers the basic iPhone repair of water damage.  1. Remove iPhone from the water and Turn it off Remove your iPhone from the water as soon as safely possible. Minimize the length of time the iPhone and water are in contact to minimize corrosion. If your phone is still on when removed from the water, attempt to turn it off. If it's off, do not attempt to turn it on. 2. Check External Ports Check any external ports (charging port, headphone jack, SIM card slot, etc.) for corrosion as well. These may have to be cleaned out with alcohol and a  Anti Static Brush , or replaced if cleaning is not practical. Pay special attention to cable ends, battery contacts, connectors, pins, and fuses, as these parts are prone to corrosion and can easily cause the phone to malfunction. Test all the buttons and features (such as the microphone, s
Read more

Free download: Ford / Mazda odometer correction tool software

Image
New Mazda OBD2 Tool is the Digital Odometers, Airbag reset and immobilizer programming cables by OBD2, it is a newly OBD2 device for Mazda Vehicle. Mazda OBD2 Tool is Mazda OBD2 Odometer correct and Airbag module repair tool, especially for Mazda vehicle from 2005-2015.It is OBD2 user friendly tool, used for calibrate odometer and airbag repair. For Mazda Digital Odometers programming and Airbag reseting Tool by OBD2 Mazda OBD Tool is used to calibrate the instrument for all CAN-bus Mazda cars from 2005 to 2015 including MADZA 3/ MADZA 6 / MADZA CX5 / MADZA CX7, as well as reset the airbag/SRS for Mazda with XC236X chip. 2017 New Ford / Mazda OBD2 Tool is the Car Digital Odometers and immobilizer programming cables, and Ford OBD2 Tool and Mazda OBD2 Tool is used to mainly perform Ford / Mazda Digital Odometers, instrument calibration and immobilizer key matching. Here, VIP Pro Shop Team will share the software download link for Ford OBD2 Tool and Mazda OBD2 Tool.
Read more