Sim Test - Asus P552W Manual

2.3.8 SIM Test

If unable to read SIM card scenario is observed, please try to
replace device's sub board first. If this still does not solve the problem,
please examining the following:
● Verify if there is any damage to the main board BtoB connector
CON1201.
● V_LDO should able to supply 1.8V or 3.3V supplies depending on
the SIM card. If the measure voltage is incorrect, it is likely that
U901 is defective.
● During SIM card initialization period, SIM_RST voltage level
should be measured at 1.8V or 3.3.V, SIM_CLK should be able to
observe a clock signal and SIM_DAT should be able to observe a
high-low transition signal. If any of the above signals is incorrect,
then it is likely that U301 is defective.
華 碩 電 腦
華 碩 電 腦
Figure 1.8 Camera Bus
GTC ■ Service Manual
27