Synthesizer Troubleshooting Diagram - Nokia NPM-6 Series Troubleshooting Instructions

Troubleshooting Instructions

Synthesizer troubleshooting diagram

Synthesizer
troubleshooting
Yes
Set with RF controls:
Active Unti = Rx
Operation mode = Continuous
Check with RF probe:
Check with RF probe: -4G VCO out signal
-4G VCO out signal
-3589.6 MHz (EGSM900)
- 3589.6 MHz (GSM900)
-3495.6 MHz (GSM1800)
-3495.6 MHz (GSM1800)
-3760 MHz (GSM1900)
- 3760 MHz (GSM1900)
Level >-10dBm (*
OK ?
No
VCO out signal level<-10dBm
No
Check output signal on
1 GHz span
Signal found on
incorrect frequency ?
Yes
Check with oscilloscope:
VCO control voltage
from VCO pin
0V ?
No
Check with oscilloscope:
VCO control voltage
from VCO pin
>4.0 V ?
Page 22
Figure 14:
*(When 2.5kOhm passive probe is used,
correct the measurement by +34 dB
Yes
Synthesizer
OK
Yes
Check balun
output levels and
solder joints
OK ?
No
Replace
faulty
component(s)
Check with oscilloscope:
-4G VCO Vcc = 2.7V
No OK ?
Yes
Check balun
output levels and
solder joints
OK ?
Yes
Check VCO control
loop components
OK ?
Yes
Replace
ãNokia Corporation.
CCS Technical Documentation
Yes
Yes
Replace
No
Baseband
troubleshooting
No
Replace
faulty
component(s)
No
VCO
VCO
Issue 1 01/03