We got a iPhone 6 Plus from our customer, the problem of this iPhone is shows black screen after power on, and this problem has been repair, but no effect. When we got the iPhone, we can see that it has been dropped and the display screen was broken. Now, Vip Pro Shop Team will take 6 steps to solve this problem.
1. Disassemble the iPhone and the power short-circuit current is more than 700 mA,
observe the motherboard under the stereo microscope. As shown in picture 7-6-1
and 7-6-2.
2. Backlight IC is placed
directly on the top, we also find that the screw column is broken, there must
be a broken line. After the measurement of power supply, it shows PP1.8V,
PP1.8_SDRAM are short circuit. 1.8V power supply connected to the original
components as shown in picture 7-6-3 .
3. Decisively
take off the black touch welding on the 5 large chips and some capacitors, 1.8V
short-circuit is excluded. Check the PP1.8_SDRAM power supply, and the original
components are shown in picture 7-6-4
and 7-6-5.
4. There
are 6 chips in this power supply, a little bit of trouble to take them off, so
direct burning the device. When the current is adjusted higer slowly, it is
found that the power IC is heated and the short circuit fault is removed after
taking off. Switch on the power IC and boot, the current 0mA--60mA jump back
and forth, this situation is mostly CPU did not identify the upper layer caused by, is the upper blowing empty?
5. The
screws column is damaged, blow the screws, the 6P right screw has a 12C bus wires,
and if the 12C is short-circuit, it will cause the upper layer cannot be
identified. Scraping the screw column and finding a broken one, so we solder
with jumper wire. As shown in picture 7-6-6 .
6. After
the wire is repaired, the current jumps normally. Replace the chip directly,
soldering jumper on black touch M1 pin. As shown in picture 7-6-7 .
Finally, handle
them all, the iPhone 6 plus can be turned on normally. As shown in picture 7-6-8 .
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