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CONFIDENTIAL
Service & Analysis Center Europe
Training Team
version 1.0 / 05.11.1999 Page 13 of 37
Phone switch it self off
C136 10μF/10V
•
Check, if the handset doesn't switch off with 3V SIM-Cards
•
Check that the 5V VSIM voltage on the capacitor C136 is approximately 4,8V-5,2V with
maximal 350mVpp noise overlap (view the diagram below)
Phone intermittend switches off
Check if this happens
only with 5V SIM-cards
and if the phone works
probably with 3V SIM's
Change C131 if the
noise is higher than
350mVpp
Check X101 and X102,
if poor soldered, bent
or soiled
Check amplitude of
32,768KHz square
wave at C149
Check amplitude of
13MHz
RF Clk C301 (2,8Vpp)
Check VBB 2,8V DC
on
C117
Resolder, change or
clean the connector
Change or check
soldering of B100,
C147, C148, C153,
N100
Change or check
soldering of G701,
V702...
Change or check
soldering of N100,
C117
not oK
not oK
Check the 5V
supply voltage on
C136 with an
oscilloscope
oK
not oK
not oK
oK
oK
not oK
oK
not oK