跳至主要内容

Solution: iPad mini2 No Backlight and No Display

We are going to repair a iPad mini 2 today, the main problem is that the display and backlight not working now. How to repair the problem with the best solution, let's check in the article.

Open the iPad Mini 2 to observe, we can see that the lower half of the motherboard is water damaged. Check the motherboard under the magnifying glass carefully. The power supply and the display interface are corroded badly.

First we deal with the power part, and then carefully deal with the display interface, because this iPad is the display and backlight problem, when finished processing, one of the resistors fell down, check the schematic diagram on WUXINJI dongle, we found it's the light IO data interface, this resistance is 1 ohm.

 

The ground resistance value was measured by Fluke digital multimeter at the display interface after the short connection with jumper wire. It was found that there were four places where the resistance value of the pin have no resistance value.

Short connect one by one, it has display but no backlight, so we concentrate on the high voltage side  at this time, we found that the backlight positive pole and the interface are corrosive under the microscope,  so we slowly scrape with a knife, and then weld with 0.01mm Jumper Wire, to prevent loose weld when install the display screen.


Now we install the iPad mini2 to test, the display and backlight problem is solved now.

If you think the article is useful, you can get more information from www.vipfixphone.com

评论

此博客中的热门博文

Solution: iPhone X Won't Turn On

According to the customer's description, the iPhone X would not turn on after it drop accidentally. Then the cell phone reports error 56 when restore it. How did this happen? Let's test and repair step by step. Since iPhone X motherboard 2 layers are connected through the middle column, the solder points are very easy to get dropped. so we guess that the solder points from NFC chip to the CPU part have fell off. Disassemble the iPhone X by iPhone opening tools , remove the upper board off the main board, when separate the main board we see there is a row of points have fell off. Check the location map on WUXINJI dongle , it is surrounded by a ground wire, in fact, there are 6 useful points dropped. The ground wire does not need to be filled, the 6 useful points are added by professional phone welding tools. These are the signal wires of the NFC chip, so the iPhone X would report error 56. Then the tin of the middle column is repaired by iPhone X BGA reballing ste...

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...

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...