A Lenovo N440A laptop, can enter windows system, but display green screen. According to the experience of repairing, should be RGB circuit problem.
The display is normal when connecting an external monitor, so exclude the graphics card reason. Remove the screen cable to test, the cable is ok. Then doubt it is interface problem of motherboard. Check the resistance value between interface and GND. All are ok.
After checking, found the Pin4 and Pin5 are short circuit in U4, and capacitors C6,C8 are short circuit, too. So removed U4 and C6,C8, still there are short circuit. So removed KE5M6U2654 chip. the short circuit phenomenon disappear.... read more
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