跳至主要内容

Fixed: iPhone 6 Plus Fails to Reboot Problem

Received an iPhone 6 Plus from a customer, the iPhone 6 Plus touch IC was replaced before, but it could' t reboot after a week. Before starting to repair the device, we need to check the parts that moved by the last repairman.


Connecting DC power supply it does not leak, the starting current stays on more than 400 mA. As shown in picture 12-3-1.


Considering the touch IC has been replaced, the last repairman directly took the black touch off without welding jumper wire on touch M1 pin(6P can still boot normally without installing black and white touch), but the current is same as before, measuring the starting voltage we find the iPhone 6 Plus NAND 1.8V and I2C bus 0.6 V, so we doubt it is the iPhone power IC problem. With the power on, it is indeed hot, with 400 degrees we quickly take the power IC off, according to the symptom, it's necessary to confirm whether the power supply IC is damaged, a good method is to measure the pin resistance.



The results of this 6P is measured as the power of IC to 1.8V white touch power supply is short-circuit, now it can be judged that 1.8V power supply short circuit pulled down the power of NAND and bus, removing the white touch chip, short circuit fault is solved now, welding jumper wire on black touch M1 and replace new chip, the iPhone 6 Plus is successfully fixed here.


Read more cell phone repair knowledge at www.vipfixphone.com

评论

发表评论

此博客中的热门博文

iPhone 6 Display Failure after Replacing LCD

The iPhone 6 display is black after replacing LCD. After checking, the diode data of display socket is normal and all power supply for iPhone display IC  output is normal. Testing by  DC power supply , we find the iPhone current is abnormal. When press the iPhone power button, the boot current is obviously large. The current reached 100mA when press the power button. After remove the display tube, the current still the same, which means there is a short circuit. Measure the voltage output of each circuit of power supply with Fluke 15B+ Digital Multimeter , then surprised to find that there are really short circuit places. LD010 is short circuit; we suspect that the filter capacitance on the circuit has been penetrated. After remove the iPhone power control IC , we found it is ground short circuit. Open the WUXINJI Dongle  to check the iPhone schematic circuit, we found that this circuit is the display card image transmission MIPI data bus power supply. CPU brea...
发表评论
阅读全文

Solution: Why iPhone X Voltage Keeps Jumping

After getting the iPhone X motherboard 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 th...
发表评论
阅读全文

Iphone 6S Enters DFU Mode Cannot Start Fault Repair

The customer said that he did not know what the reason was. The mobile phone has been restarted indefinitely and can enter the DFU mode. However, when the flashing machine fails to enter the recovery mode from the DFU mode, and then the mobile phone is connected to the computer for 5-10 minutes, it automatically enters the recovery mode. After we received the 6S that could not be started, we disassembled the power with iphone engraving tool and turned on the power to 100mA. First of all, check if you can connect and read the DFU mode after connecting to the computer. Wireless DFU can not exit, we can only brush the machine to view the error. Refresh Aisi and iTunes respectively. If you stuck on the progress bar for a long time, it is very likely that the error is -1. If the progress bar does not enter, you can roughly determine the probability of a CPU failure. Now we need to see if there is a problem with the hard drive. First, use DC power supply for iphone repair, the hard disk o...
发表评论
阅读全文