K850
1203-2528 rev. 1
TROUBLESHOOTING
FM Radio Problems
TROU
B
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H
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OTIN
G
START
Go to
Service Tests and
Perform:
Speaker and
FM Radio Test
Fault trace SW
Audio and FM Radio
FM Radio
Audio Output
Loudspeaker
Frequency
According to
Instrument Settings
Set FM Radio
Yes
No
3.8 Volt DC
at MP 151 (ST2282)
and 1.8V at
MP 154 C3305
Any signal at
MP 156 (C3145)
MP 155 (C3146)
Yes
Signal
Ok
Claim
System Connector
X2400
SL 5 Replace
N2000
SL 4 Scrap
Yes
SL 4 Replace
N1400
SL 5 Replace
L3300 and C3306
No
Replace
System Connector
X2400
Load ITP SW
into the phone.
Use TRS Fixture
Connect VBATT and
DCIO/SEPI
Use Fault Trace SW
Speaker and
FM Radio Tests
working properly
No
Replace
N3101
PHF
working properly
during
Voice call
No
Yes
Yes
Can you
hear 1KHz ton at
TRS Fixture
Loudspeaker
Yes
Replace
N1400
SL 4 Replace
V2425
SL 5 Replace
L2405 and C2434
Signal
Ok
Claim
Component
SL 5 Replace
N2000
SL 4 Scrap
SL 5 Replace
N2000
SL 4 Scrap
Disconnect:
DCIO/SEPI Cable
Connect:
Customized FM Radio Cable
Black Lab Plug to
TRS Fixture GND Input and
PHF Connector to the Phone
System Connector
Signal Generator
Instrument Settings:
Frequency:
Use free Freq. Channel
Example:
103 MHz in Sweden
Amplitude: 25.0 uVrms
FM Dev: +/-22.5 kHz
FM Rate: 1kHz
Yes
No
No
No
FM Radio problems
Signal
At MP 142 (X1400
BT_ANT)
Is
MOD 1 Freq.
Minimum 230 KHz
higher then
MOD 0 Freq.
No
Replace
N1400
Yes
-20dBm at
MP 142 (X1400
BT_ANT)
(
±5dBm
)
Yes
Yes
All channel
passed
Replace
BT Antenna
and clean
X1400 and X1401
Yes
Replace
N1400
No
-15dBm at
MP 78 (Z1400 Pin 1)
(
±5dBm
)
No
SL 5 Replace
C1402 and L1402
SL 4 Scrap
Yes
-15dBm at
MP 144 (Z1400_Pin 5)
and
MP 145 (Z1400_Pin 7)
(
±5dBm
)
No
Replace
N1400
No
SL 5 Replace
Z1400
SL 4 Scrap
Yes
26 MHz Signal
At MP 148 (R2118
BT_CLK)
No
No
2.7 Volt DC at
MP 14 (ST2212
VBT27)
Yes
1.8 Volt DC at
MP 9 (ST2208 VDDE18)
and 2.7 Volt DC at MP 34
(ST2213 VDIG)
Yes
SL 5 Check C2214
and C2215 then
Replace N2000
SL 4 Scrap
No
Replace
N1400
Yes
C2205
Short circuit
No
SL 5 Replace
C2205
SL 4 Scrap
SL 5 Replace
N2000
SL 4 Scrap
No
Yes
START
Flash the phone with the
EMMA SUCR SW and retest the phone.
If successful claim SW Flashing
If not then continue with
Bluetooth problems TRS guide.
Fault trace SW
TX and RX
Bluetooth
Channel 0
Set MaxPwr MOD 0
Use
Spectrum Analyzer
Instrument settings:
Frequency: 2402 MHz
Span: 1MHz
Amplitude: -5dBm
Use Peak Search
Fault Trace SW
TX and RX
Bluetooth
Channel 0
Set MaxPwr MOD 1
Use Spectrum Analyzer
with the previous
instrument settings
Change the
Bluetooth channels
In Fault Trace SW
and test the output.
Use
Spectrum Analyzer
Span 10MHz
Use Peak Search when
changing the channel.
Note:
1MHz channel spacing
Load ITP SW
Into the phone
Use TRS Fixture
Connect:
VBATT and DCIO/SEPI
Use Fault Trace SW
More than
60KOhm
between MP 148
(R2118) and
PBA GND
No
Replace
N1400
SL 5 Replace
D2105
SL 4 Scrap
Yes
Bluetooth problems
/ Bluetooth Problems
SEMC Troubleshooting Manual
17
(101)