6S 4013 ERROR: Fix iPhone 6S unknown error 4013

We received an iPhone 6S with 4013 error from our customer, we can see there is a trace of water. For this water-damaged iPhone, mostly it's the problems of the iPhone motherboard. We need to disassemble the iPhone 6S to check the iPhone motherboard.

After disassembling, measure the iPhone 6S by DC power supply, the current is stuck at around 80mA, we confirmed it is in data cable mode. Install the iPhone, and use iTunes to restore it, but the fault is still there, the iTunes still reports unknown error 4013.

Now we need to check the iPhone baseband circuit, whether the iPhone baseband power supply is short-circuited, whether the resistance value is normal, whether 19.2 clock is normal, we can replace it with a better iPhone baseband CPU, and then restore the iPhone again, if the restore process bar can move smoothly, then possibly it's the problem of the iPhone baseband CPU.

Disassemble the iPhone, we found the area around the iPhone baseband is corroded seriously; we suspected the iPhone baseband power is damaged. Replace the iPhone baseband power, restore the iPhone 6S, the fault still exists.

Remove the iPhone baseband CPU cover shield by Titanium Alloy Tweezers, there is no traces of water around the iPhone baseband, the iPhone baseband is good.

Put iPhone motherboard under the Stereo Zoom Microscope to observe, we found the screw hole BS0502 has been penetrated, there are several circuit lines in the lower layer board are disconnected . Connect those broken circuit lines one by one, and then install the iPhone.

Now use iTunes to restore the iPhone 6S again, it succeed.

Summary: this 4013 error is not caused by a iPhone baseband problem, it's caused by the penetrating screw hole causing the iPhone CPU works abnormally.

Liquid-damaged iPhone 8 Plus won't turn on with hardware solution

An iPhone 8P fell into the water last night，and then the iPhone 8 Plus won't turn on. The customer sent it to us in the next morning, after we received the iPhone, seems there are many water coming into the iPhone. The customer told us that the iPhone doesn't important, just want to extract the data from iPhone. Now, we are going to fix it.

 

Take out the iPhone motherboard, clean it up and dry it. After drying please don't supply power to it, we need to observe that which position has more water, so we can avoid burning other circuit components because of the power supply.

After checking, we found the area that was seriously damaged by water, there are 6 pieces capacitors on the left corner are corroded, directly remove it by the brush. Because they don’t affect the boot of the iPhone, so we don't need to deal with them now.

Put iPhone under the Trinocular Integrated Microscope, we found these two capacitors also was burned, after testing, they all in short-circuit status. Open the ZXW Dongle to check iPhone schematic diagram, we know that the C4910 leads to the iPhone ringtone amplification U4900, and the C3310 leads to the iPhone charge tube U3300. Check these 2 ICs, there are no trace of water, possibly is these 2 ICs are damaged.

Take these capacitors out and test the iPhone motherboard, the iPhone layer board doesn't short, re-fill these capacitors, and then test it with DC power supply, the boot current tested is normal. After dry out the iPhone display screen, connect it to the iPhone, and then power on iPhone, the iPhone screen can be lit, but it turns darkness gradually.

Replace it with the new iPhone display screen, and test it again, now the iPhone screen works properly, and all functions tested are normal.

How to repair iPhone 7 No Service (iPhone baseband problem)

Yesterday, a customer sent us an iPhone 7, the problem of this iPhone is that the iPhone 7 has no service after expanding iPhone Nand flash momory storage. After brushing it with iTunes, the iPhone is still no service, and it won't activated. 

Use screwdrivers to remove the screws next to the iPhone lightning port, and then put iPhone 7 on the CPB screen separator, after a while, we can open the iPhone 7 easily. 

Take out the iPhone motherboard,  use digital multimeter to measure the power supply capacitors around the iPhone baseband power IC, we found the PP_1V0_SMPS5 is shorted. Generally, this case is caused by a short circuit of the iPhone baseband. Remove the iPhone baseband power, and then measure the PP_1VO_SMPS5 again, it's still shorted.

This is a designed flaw of iPhone 7 Qualcomm version, the iPhone baseband S5 power grounding connect point seems to be disconnected, but not, and it cause iPhone baseband burned.

The solution is put iPhone motherboard under the Stereo Zoom Microscope, re-connect the S5 grounding connect point, and re-install the iPhone baseband power, borrow a PP1V8_SDRAM on the C3211, pass through a 2.2K resistor to C5701_RF, and then forcibly pull up PP_1V0_SMPS5.

Now, use digital multimeter to measure the iPhone 7, the data measured is normal. Assemble the iPhone 7, turn it on,  step by step to activate it. After entering the IOS system, the iPhone 7 has service, now the iPhone 7 is back to normal work. 

How to repair iPhone 6 screen failure (blurry screen)

Yesterday, we received an iPhone 6, which has screen failure, the iPhone screen is blurred,  we try some softwware solutions, but not working, we also try to fix it by replacing iPhone scree, but still failed. So, we suspected that it's the iPhone motherboard problem.

Use screwdriver to remove the srews next to the iPhone lightning port, put iPhone 6 on the CPB screen separator for a while, and then open the iPhone 6. Remove the iPhone display assembly and iPhone battery, and then take out the iPhone motherboard.

Observe the iPhone motherboard,  we found the upper part is seriously deformed. Use digital multimeter to measure the grounding resistance value of the iPhone display socket J2019, the resistance value all is normal.

Put iPhone motherboard under the Trinocular Integrated Microscope, remove the iPhone display IC U1501.Measuring the grounding resistance value of the iPhone display IC J219, we found the A4 pin is shorted, A4 pin touch 5.7V power supply, it is connected to iPhone black touch IC and some filter capacitors. 

Because the upper part of iPhone motherboard is deformed seriously, and the iPhone black touch IC is easy to damage, so remove the iPhone black touch IC.  However, it is still short-circuited after remove the iPhone black touch IC, seems it's not the problem of the iPhone black touch IC. 

Next we need to use QUICK 861DW hot air rework station to remove the filter capacitors that connect to it, after remove the filter capacitor C1577, the resistance value is back to normal. Re-install the iPhone black touch IC and iPhone display IC.

Now, install the iPhone, charge the iPhone 6 with iPhone lightning cable, after a while, power on the iPhone, now we can see Apple logo appears on iPhone screen, the iPhone screen displays normally. Test other functions on iPhone, all works perfectly. 

Repair guide: iPhone 6S Plus no service after WIFI failure fixed

The iPhone 6S Plus has WIFI failure, after we fix it by ourself, the iPhone has no service, why it that? how to repair this problem? Here is an repair guide.

Firstly, we need to test the iPhone 6S Plus. Turn on iPhone 6S Plus, insert the SIM card, the iPhone shows "no service". Check iPhone carrier signal, it can be manually searched, but unstable.

Continue testing, the signal is normal when you turn on 4G in Cellular Data, it can connect to the 4G network. It's normal to make phone calls and browse the Web，but the signal is bad. Turn off 4G, and then choose 3G and 2G, both of them are showed no service.

The 4G signal can be searched normally, but 2G and 3G are no service, we suspected that the fault should be an iPhone antenna switch or a 2G amplifier.

Is it an error in the antenna switch frequency selection? We decided to replace the antenna switch and test it. After remove the antenna switch, use digital multimeter to measure the diode data, we found the 21th PP_2V8_LD014 power supply of the ULASM_FR antenna switch is grounding short-circuited.

Open the WUXINJI Dongle to check the iPhone schematic diagram, we found the PP_2V8_LDO14 is connected to many places, one of them was sent to the filter U_VOX_RF next to the iPhone WIFI IC.

Measuring the diode data for all the power supply of filter, we found there are several power supply circuit are short-circuited.

According to the description of the customer, we judged that the fault is that the tin ball of the filter next to the iPhone WIFI IC was burned when he repairing the iPhone WIFI IC.

Use QUICK 861DW hot air rework station and Titanium Alloy Tweezers to remove the U_VOX_RF directly，and then turn on iPhone to test, now the 2G, 3G and 4G signal can be searched normally, and the signal tested is normal.

After re-installing the U_VIX_RF, assemble the iPhone, turn on iPhone 6S Plus, now the iPhone signal is normal , it has service. Test the functions on iPhone, all functions tested are normal.