Open phone, power on boot, test Figure 3 displays the interface pin voltage with a multimeter, 4 pin voltage -2.1V, abnormal, normal values for -6.4V;5 pin voltage -1.5V, abnormal, normal value should be -5V. C40 and C41 damage suspected peripheral capacitance, the modulation of the meter resistance, respectively, each in red and black pen touch a C40 and C41 two feet, two feet when it comes of C41, display returns to normal. Then replace the C41, troubleshooting.yAhservice manual download site