跳至主要内容

Fixed: Why Your iPhone 6S Has No Signal

iPhone 6s signal part is mainly composed of baseband CPU--U_BB_RF, baseband power U_PMU_RF, intermediate frequency U_WTR_RF, 2G antenna switch ULASM, 3G/4G antenna switch UHASM, preamplifier UDIVA_RF, 2G power amplifier U2GPA_RF, 3G power amplifier, 4G power amplifier UHBPA_RF and power supply U_QPT_RF.


The main faults of the iPhone 6s signal are as follows:

- Completely no signal

we should make clear the baseband is starting properly, then input *#06# in the dial-up interface, if the iPhone 6s screen does not appear a string of numbers (IMEI code) which means that the baseband does not start properly, for some iPhone devices, you can see IME but if the iPhone screen does not display the IMEI after entering *#06# on the dial-up interface, it also means that the baseband doesn't start normally, this is usually caused by the baseband CPU false welding, or it's also possible that baseband power is false welding, the solution is to replace new iPhone 6S CPU or baseband power parts.

If you input *#06# and see IMEI codes, it means the baseband belongs to normal start, in this case, try to install different SIM card separately, if all the SIM cards you install have no signal, the problem in the public sector, or if IC emission power supply problems, this possibility may be a bit bigger, the base band CPU or baseband power may also cause the situation. Replace new parts can solve the signal problem.

- Part of SIM cards have no signal

If there is no signal for part of the SIM card, for example, there is a 4G network but you can't call on the phone. It means that there is a problem in the 2G transmitting part, since the mobile 4G needs to switch to 2G when it calls, which is usually the problem of 2G power amplifier or 2G antenna switch, replace new parts can solve the problem.

If there is 2G but no 4G signal, the problem is on the 4G amplifier and the iPhone 3G/4G antenna switch. Replace new parts can solve it!

Any technical questions and knowledge about cell phone repair you want to know, please visit on www.vipfixphone.com

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...

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...

Guide: iPhone 7 Plus Camera Fault Repair

iPhone camera failure is common for most of cell phone repair technicians, today, we're going to fix iPhone 7 Plus camera. According to the holder's description, the front small camera is normal while the rear camera fails to take photos, when turn on it, the iPhone 7 shows black screen. Let's start from easy repair operation: directly replace the iPhone camera to have a test.  Note: Pay attention that two camera are connected together. When disassemble the iPhone 7P rear camera , you need to pry up from the left side.  The fault is same as before after replacing a new rear camera. We tested before, the iPhone 7P double camera is rely on the bigger camera to get image, as shown in 15-5-1, the corresponding part on iPhone 7P motherboard is J4501 pin, the resistance value is normal after testing with Fluke 15B+ digital multimeter , it reminds of us that iPhone6 Plus also encountered this phenomenon, the power supply part has some problem. By checking on  WUXINJ...