Hello Every One ,

Krish Mobile Training Institute

This is an oppo mobile. The customer brought this mobile to our shop. The technician asked the customer what is the problem with the mobile.The customer said that if the charger is connected to this mobile, the CHARGING is not increasing. The technician said that he will check the mobile and repair it.

Krish Mobile Training Institute

Now come and see the problem in this mobile :

• First we need to open the mobile back panel.
• If you connect the 6 in 1 charger to the mobile, it does not take any ampere.
• This problem is called fake charging problem.
• Already another technician tried sub board, b to b strip, battery, sub board to main board jumper, almost everything.
• Separate the mother board from the mobile.
• Another technician also changed the BQ ic.

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• First check all the voltages.
• Connect the charger and check whether the V-bus voltage is 5.2V.
• Check if the voltages are coming on the bq ic.
• vph voltage is not coming, v-bat voltage is also not coming.
• 1.8V should come on i2c lines, but it is not coming.
• Let’s change the bq ic once.

• Bq Ic has been changed.
• After changing the bq ic the vph voltage came.
• V-Bat Voltage has also arrived.
• 1.8 V will come on pin number 7.
• Voltages are all OK.
• Check if the problem is solved once.

• If checked, 6 in 1 charger takes 1.0 amp and again drops to 0.6 milli amp.
• 0.6 milliampere compared to charging is not stored.
• The problem is still not solved.

Let's check once in a cool test :

Krish Mobile Training Institute

• Once we see the pins configuration in the cool test.
• Check the Gr value on the 24 pins of the Bq IC.
• Gr value is good on all pins.OL comes only on the 10th pin.
• Let’s remove the bq ic again and check the gr value of the ground.
• If you remove the bq IC, you will see OL on the 4 th pin.
• Above the 7th pin high value came.
• 8th, 10th, 11th pins also got OL above.
• It is a problem if there is a high value here. Such a high value should not come.
• That is the problem.

• A 10k Ohms register is placed next to the bq ic.
• Including that capacitor value, the Gr value is high here.
• Once that register should be removed.
• After removing, check the value on both sides.

• On the one hand, this is the 1.8V line that comes from power ic.
• On the other side is the line from cpu.
• The side connected to cpu does not get the value of gr.
• This line is open from cpu itself.
• What is the solution for this, cpu should be reballed.
• If the problem is not solved, the cpu should be changed.
• But what the customer told us is that if the problem is that big then no, we will exchange the mobile.
• That’s why we returned the mobile.

video link is given in the below :

thank you by team k.m.t.