The customer's iPhone 5S was experiencing blue screen errors and incorrect battery percentage readings after replacing the rear case. This was caused by improperly installing a screw that broke the circuit board and missing components on the battery interface. To solve this, the technician removed the faulty screw and jumped a wire to reconnect the circuit. They also resoldered a missing capacitor and inductor on the battery testing circuit, which fixed the blue screen and battery percentage errors.

1. iPhone 5S blue screen error and battery percentage
error
The mobile phone plays important role at our work and
life. It becomes very smart and convenient. but that still
doesn't mean that they won't go wrong. No, if you think
so, when your phone has problem, you will not do
anything. Now vipprog engineer sort out a guide to solve
iphone 5s blue screen and battery percentage error. If you
will try you need some tools, which also makes it safer
and prevents you from causing more damage. You can
choose vipprogrammer.com get some high quality phone
repair tools.
ISSUE:
After the customer changed the rear case of his Chinese
32G iPhone 5S, many problems appeared. For example,
it reboots indefinitely when in charge and reboots when
the screen turns blue and reboots. The battery shows
incorrect battery percentage, as shown in below picture.
The customer recalled that when he install the screen and
fix the shielded iron, he install the wrong screw leading

2. to breaking the board. Meanwhile, at the end of battery
interface there miss some components because of
improper treatment.
SOLUTION:
The first problem is blue screen and reboot.
1. According to the customer’s feedback and my own
experience, the blue screen caused by man is due to the
wrong installed screw which breaks through the screw
hole and the circuit in the hole disconnects when fix the
shielded iron. Remove the screw and scratch the circuit
under the screw hole to jump a wire. Use insulating
green UV Solder Resist to solidify it. The blue screen
will not appear again. How to jump a wire and solidify

3. green oil is shown in below picture.
The second problem is that it will reboot when in
charge and battery shows incorrect battery
percentage.
2. These are caused by faulty battery voltage testing
circuit. Customer said that some components missed at
the end of battery interface. Observing under microscope,
we can see that a component misses at the end of battery
interface and the other one is going to drop off, as shown
in below picture.
3. After checking the bitmap of iPhone 5S, we know that

4. the missing component is capacitor C279 and the other
one is inductor FL11, as shown in below picture.
4. After checking the circuit diagram, we know that
capacitor C279 is the filter capacitor on battery pattern
test circuit and the inductor FL11 is the insurance
inductor on battery pattern test circuit. Their location is
shown in below picture.
5. Fix the capacitor C279 and resolder the inductor FL11,
as shown in below picture.

5. 6. Then assemble and turn on iPhone. The blue screen
and reboot do not happen and we can get into IOS
normally. Battery shows correct battery percentage.
Trouble is removed.