Lg900

For E900 there is something to ceck first you can ceck the connector b2b CN801 if all ok you need ceck the resistor and cap near this connector and at pin 3 ceck voltage 3v and pin 4 voltage 2,6 in alternative if you have you can replace the complete sim board, if all ok and not work you need ceck oscillator X501 on main board and also if this is ok ultimate is to ceck U507. At the end need swap board because missing signal from Cpu.

I resolve in this motod.. Check the voltage 3,0v in pin 3 and 2,6v in pin 4 on the touch connector CN801. if the voltage is ok, rework all pin the touch connector whit welder stylus. I solved whit rewok in three phones LG E900..