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Ontact service, Cobba, Parallel – Nokia 3210 User Manual

Page 13: Serial bus fail, Phone intermittend switches off

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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