跳至主要内容

Repair: iPhone 6 Display Failure After Replacing Battery

We are going to repair iPhone 6 with display failure, we get to know from customer that the situation happens after the battery was replaced. Why this happens? How should we test and repair?
The iPhone 6 works normally before the battery is replaced, but the iPhone is not displayed after the battery is replaced. This fault is usually due to the client accidentally installing the long screw in the short screw position and then the screw under the circuit. It was pierced.

Opening the iPhone and remove off the iPhone motherboard. Measure the resistance value to grounding for display socket J2019 with Fluke 15B+ Digital Multimeter, we find the resistance value to grounding for 14 pin AP_TO_LCM_RESET_CONN_L is infinitely large, which is clearly disconnected.

There is the trace of a breakdown for left screw column BS2502 after observing it under the HDMI Camera Stereo Zoom Microscope, scrap it and re-connect the disconnection. Measure the resistance value to grounding for display socket J2019 14 pin AP_TO_LCM_RESET_CONN_L with multimeter, the data is normal.

Install the iPhone and test it, we find the iPhone volume button not working, and the WIFI cannot be recognized.

Measure the resistance value to grounding for iPhone volume button socket J0802, it is infinitely large, and perhaps it is disconnection. This circuit line is on the third floor of the left screw column that near the edge position, carefully scrape it and then re-connect it.

There are 2 reasons why WiFi can not be identified, one is the iPhone motherboard is disconnected, the other is the iPhone WiFi module IC problem. Remove the iPhone WiFi module IC and measure the effect of resistance on the grounding of the pad, no abnormal was found. Replace the new iPhone WIFI module IC, install iPhone and test it.

Both the iPhone volume button and WIFI functions are normal now, repair ends up here! If you want to get more information about cell phone repair, please check on 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