跳至主要内容

Solution: iPhone 6 Weak Signal Problem


We received a iPhone 6 today. The main problem is that the signal of the iPhone 6 is so weak that the user can't use his iPhone properly. We'll give the best solution for this kind of fault, let's check it in the article!

After receiving iPhone 6, observe the appearance of iPhone without obvious physical damage.

Disassemble the iPhone 6 and connect iPhone logic board to the DPS DCpower supply to measure its current, the current is normal.

Press the iPhone power button to turn on the iPhone and enter the iOS to check the iPhone signal. After measurement, the signal is abnormal, very weak.


Based on previous maintenance experience, there is an inductor L4608 powered by B + to the iPhone antenna switch, and we can open the Five Star Set package to look at the iPhone sketch to find it.



After find out the problem, we need to short connect L4608. Put iPhone logic board under the StereoZoom Microscope, use QUICK 861DW hot air rework station to solder a jumper wire on L4608.


Install the iPhone and test it, the iPhone signal is back to normal，now the iPhone signal is full and strong.

More useful cell phone repair information please check on www.vipfixphone.com

评论

发表评论

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...
发表评论
阅读全文

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