5-2
Trouble shooting
5-1-2 Abnormal initial operation (2.8V voltage source)
Press PWR Key
Normal initial
display on LCD?
END
LED on?
Check the LED and its neighboring
circuits. Replace if required.
RAM_CS signal
outputted from U100
pin P14,N4?
Check MSM board U100
TCXO CLK
applied to U140 pin2
CHIP X8 CLK
signal outputted from
U100 pin A14?
TCXO CLK
signal outputted from
U140 pin4?
Check VCTCXO Output.
Check U140 and its neighboring
circuits. Replace if required.
Check the LCD pins and its neighboring
circuits. Replace if required.
Check MSM board U100
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
