Nokia 8310 Repair Hints page 9

Customer Care Europe & Africa
SCCE Training Group
© 2002 Nokia Mobile Phones
CHAPTER 4 SIMCARD-FAULTS
X386
In case that phone messages "Insert SIM card" on LCD, first of all check mechanical appearance of SIM card reader X386. If
contact springs are bent, soiled or corroded you have to change the sim reader.
R388/D200/D400
If mechanical appearance of SIM reader seems to be ok but fault persists, check with an oscilloscope if SIM lines at SIM reader
pin 1-4 are pulse to 1.8Vpp / 3Vpp as shown in the chart below. Signals are slightly different between pin 1-4 but the
amplitude always is 1.8Vpp / 3Vpp.
In case that the above mentioned signal is not measurable at one or more simlines, check SIM lines for shorts to ground.
Resistance of simdata- and VSimline normally is > 200kΩ, resistance of SIM reset- and SIM clock line normally is ~ 4.5MΩ.
If resistance of any line is not ok check parts the SIM lines consists of (R388, C203, C389).
In case that resistance of all lines is ok but fault persists, EMI-filter R388 may have internal interruption. Change part and retest
the phone. It also is possible that UEM D200 or UPP D400 are responsible for this fault. Due to the missing possibility to
rewrite phonedata after changing UEM D200 you should not change this part.
© NMP 2002
Display message
"Insert SIM card"
Check at
SIM reader pin 1-4
if pulsed to ok
1.8V/3Vpp
nok
Check SIM lines for
ok
shorts to GND
nok
Check / change EMI-filter
R388, C203 and C389
CONFIDENTIAL
NHM-7
Date 28.02.2002
Check SIM card if dirty, check
mechanical appearance of SIM reader
and SIM cover, change parts if
necessary
Check / change R388, D200 or D400.
If this does not solve the problem
PCB is faulty in all probability
VSIM (1)
SIMReset (2)
SIMCLK (3)
Checked by:
SCCE Training Group
9 (18)
Repairhints
Version 1.0 Approved
GND (6)
n.c. (5)
SIMData (4)
Approved by:
SCCE