Service Manual
Page 99
TROUBLE SHOOTING 4.12 SIM Detect Troubleshooting USIM Initial sequence of U250/KU250 is run? 4. No Change the Main board End Check J300 End - 100 - YES Change SIM card Yes NO Yes Work well? USIM_P_CLK is : USIM_CLK,USIM_RST,USIM_DATA triggered → VREG_UIM_2.85V go to 2.8V → USIM IF work Start Re-insert the SIM card Work well? No VREG_UIM_2.85V is 2.85V?
TROUBLE SHOOTING 4.12 SIM Detect Troubleshooting USIM Initial sequence of U250/KU250 is run? 4. No Change the Main board End Check J300 End - 100 - YES Change SIM card Yes NO Yes Work well? USIM_P_CLK is : USIM_CLK,USIM_RST,USIM_DATA triggered → VREG_UIM_2.85V go to 2.8V → USIM IF work Start Re-insert the SIM card Work well? No VREG_UIM_2.85V is 2.85V?