Sharp SGH-F250 - Manual (Page 29)

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9. Flow Chart of Troubleshooting
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9-1
9-1. Power On
Check the current
consumption more than
100mA
Check the VBAT
more than 3.3V
' Power On ' does not work
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END
No
Yes
C319(VISA) = 2.6V?
Check the Battery
No
Yes
Check the
VDD_IO_LOW_1.8V
of U305 is more than 1.8V
Check the related circuit
No
Yes
Check U305
VDD_IO_HIGH_2.9V = 2.9V
AVDD_2.6V = 2.6V
VDD_VIB_3.3V = 3.3V
VDD_SD_2.9V = 2.9V
VDD_PLL_1.2V = 1.2V
Check the U305 and C333, R318,
R309
No
Yes
Check the initial operation
Yes
Yes
Check the U305 and C300, C305,
R316, U302, C307, C311
Check R120
Freq = 32KHz
No
No
Check the clock R120
Yes
Yes
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