Nokia 6110 - Your Phone Hardware; Keys and Parts Identification

PAMS
Technical Documentation
NSE–3
Disassembly & Troubleshooting Instructions
Page 18
Original, 11/97
Audio failure (1)
Uplink (microphone) and downlink (earphone) are broken
Voltage at pin 107 of MAD2 (D200)
is 2.8 V (without external audio de-
vices) HOOKDET
NO
YES
Check
R259, R260
Voltage at pin 108 of MAD2 (D200)
is 2.8 V (without external audio de-
vices) HEADDET
NO
Check
R257, R256, R261
YES
Frequency at pin 138 of MAD2 (D200)
is 1 MHz, square wave 2.8 Vpp
NO
Check
N250 (Cobba)
Frequency at pin 139 of MAD2 (D200)
is 8 kHz, square wave pulses 2.8 Vpp
YES
NO
Check
N250 (Cobba)
Uplink (microphone) is broken
Voltage at pin 6 of X100 is 1.8 V
Voltage at pin 7 of X100 is 0.3 V
NO
YES
Check
microphone, X100 and micbias
components V250...
If OK, check that micbias control line
is (D200 pin1 ) 2.8 V during a call
during a call
YES
DC voltage at pins 59 and 60 of
N250 is 1.4 V during a call
NO Check
N250 (Cobba)
YES
Analog audio signal (few millivolts) at pins 59 and 60
of N250 during a call
NO
Check
C262, C263 and PCB
routings
YES
Check
N250 (Cobba)
Digital PCM data at pin 137 of MAD2 (D200)
during a call
NO
YES