Sim Part - Samsung SGH-S300 Service Manual

SGH-S300 Flow Chart of Troubleshooting and Circuit Diagrams
2. Initial
Check and resolder LCD connector CN200
if there is s older bridhe between the pins

3. Sim Part

Phone can't access SIM card
Check the pin 1 of CN100.
Voltage = 3V?
Check the SIM
connector's (CN100)
connector's to SIM card
Check the circuit around CN100 input
Check the circuit around U601 output
and voltage supply circuitry
Initial Failure
Check the signal at the
pin 28 of U100 is
"H igh" when the phone
is boot on
YES
Check the pin 22 of
U100 is "H igh"
YES
Check the pin 4 of
OSC801 is around 2.8V
YES
YES
END
NO
YES
NO
YES
NO
circuitry
YES
NO
YES
END
SAMSUNG Proprietary-Contents may change without notice
NO
NO
NO
Check the soldered status of
6-2
Check U100
Check the U700
OSC801, R803, U100
Check the circuit related to
U100
resolder or change CN100
Check the related circuit of
CN100
Check the related circuit of
U 601 and U100