Customer sent an ipad Mini2, change the screen accidentally add electricity 15v, single board plus electric short-circuit. Detection of power, 0v slowly up to the voltage, add to 1.5v current to 2 A, remove the power protection tube, to detect a B + short circuit.as shown in picture 8-7-1.
Take out the iPad power IC , the B+ voltage still shows short circuit. In this case, we can use "Paint Rosin Method" and supply power on it. As shown in picture 8-7-2.
Because the B+ involves too much IC and capacitance, we can't make sure that which component is broken. In order to perceive the temperature, we use hand to touch it, and found the temperature of rear big audio IC is higher than others.
picture 8-7-3.
Remove the iPad big audio IC and measure the B+ circuit again, we found that the short circuit fault has disappeared. And the power supply point of big audio has obvious signs of burnout. We can check it clearly under the microscope , as shown in picture 8-7-4.
Install the power IC, power on iPad and test it, the problem is solved, the iPad mini 2 can boot now. As shown in picture 8-8-5.
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