K850
1203-2528 rev. 1
TROUBLESHOOTING
Audio Internal Problems
TROU
B
L
E
S
H
O
OTIN
G
Fault Trace SW
Audio and FM Radio
Audio Loop test
Audio Input: Mic1
Loop Mode: Analog
Audio Output:
Earphone
Apply Audio Loop
Whistle into the
PBA Mic
SL 5 Replace
N2000
SL 4 Scrap
Yes
Replace
Electret Mic or
X3105
Yes
More than
100mV AC Pk-Pk
at MP 43 (L3103 BEARP)
and MP 45 (L3104
BEARN)
No
2.2 Volt DC
at MP 106 (R3109
CCO_INTMIC)
No
More than
100mV AC Pk-Pk at
MP 37 (ST3100)
Fault Trace SW
Audio and FM Radio
Audio Loop test
Audio Input: Mic1
Loop Mode: Analog
Audio Output:
Loudspeaker
Apply Audio Loop
Whistle into the
PBA Mic
More than
100mV AC Pk-Pk
at MP 74 (X3102) and
MP 75 (X3103)
Yes
No
No
SL 5 Replace
N2000
SL 4 Scrap
More than
100mV AC Pk-Pk
at MP 1 (X3100) and
MP 2 (X3101)
Yes
No
SL 5 Replace
L3103,L3104,
L3110,L3111
SL 4 Scrap
1.9 Volt DC
at MP 74 (X3102) and
MP 75 (X3103)
Yes
No
Go to
Audio External
Problems
No
Is any of
C3137 and C3160
Short circuit
No
Replace
N3100
Yes
More than
100mV AC Pk-Pk
at MP 38 (C3137) and
MP 42 (C3160)
No
Yes
1.9 Volt DC
at MP 139 (V3101_Pin 1)
and MP 138 (V3101_Pin
2)
No
Yes
Yes
Replace
D2420
1.8 Volt DC
at MP 19 (TP3100
AMPCTRL)
Yes
No
START
Step 1: Perform
System Connector Protection Test
Step 2:
Use TRS Fixture. Connect Display
and Keypad. Connect VBATT and
perform Audio Service Tests. If all
Audio Service Tests work properly at
the fixture then replace Loudspeaker
or Earphone
If not then
Load ITP SW into the phone.
Use TRS Fixture.
Connect VBATT and DCIO/SEPI
Use Fault Trace SW
and continue with the Audio internal
problems TRS guide
No
SL 5 Replace
L3108 and L3109
SL 4 Scrap
Replace
V2405
2.2 Volt DC
at MP 35 (L3105
CCO1)
Yes
Replace
N2400
No
0 Volt DC
at MP 160
(V2405_ Pin 6)
Yes
Yes
SL 5 Replace
L3105
SL 4 Scrap
2.6 Volt DC
at MP 124 (ST2441)
Replace
Faulty Component
SL 5 Replace
N2000
SL 4 Scrap
Audio Internal problems
START
Step 1: Perform
System Connector Protection
Test
Step 2:
Load ITP SW into
the phone.
Use TRS Fixture
Connect: VBATT and DCIO/SEPI
Use Fault Trace SW
Fault trace SW
Audio and FM Radio
Audio Loop test
Audio Input: AUX1
Loop Mode: Analog
Audio Output:
AUX Earphone
Apply Audio Loop
SL 5 Replace
L2403 or L2404
SL 4 Scrap
Can you
hear at AUX
earphone when you
whistle in to the
AUX mic
No
More than
20mV AC Pk-Pk at
MP 109 (R3130 MICP_int)
and MP 89 (R3131
MICN_int)
Yes
L2403 and L2404
Ok
No
Yes
Replace
System Connector
X2400
Yes
No
No
Yes
No
Yes
No
Flash the Phone
with EMMA
SUCR SW
Yes
Yes
L2401
Ok
SL 5 Replace
L2401
SL 4 Scrap
L2402
Ok
SL 5 Replace
L2402
SL 4 Scrap
No
No
Yes
Audio Internal
Tested
Go to
Audio Internal
problems
Yes
No
More than
20mV AC Pk-Pk at
MP 88 (C3155) and
MP 87 (C3156)
Replace
N3101
Yes
SL 5 Replace
N2000
SL 4 Scrap
No
Replace
System Connector
X2400
Replace
N3101
2.2 Volt DC at
MP 86 (R3156)
Yes
SL 5 Replace
L3106 or N2000
SL 4 Scrap
No
Replace
System Connector
X2400
Disconnect
DCIO/ SEPI cabel
and Insert PHF set
Whistle into the AUX
mic
Connection
between
MP 115 (X2400_Pin 4)
and MP 111 (L2402)
Ok
Connection
between
MP 114 (X2400_Pin 3)
and MP 110 (L2401)
Ok
More than
80mV AC Pk-Pk
at MP 112 (L2403 SPL) and
MP 113 (L2404 SPR) When
whistle in to the
AUX mic
Audio External problems
/ Audio External Problems
SEMC Troubleshooting Manual
16
(101)
