Nokia NSW-5 Series - 19.44 MHz Osc. Troubleshoolting

NSW-5
Disassembly and Troubleshooting Instructions
PAMS Technical Documentation
Page 46
Issue 1 10/00
 Nokia Mobile Phones Ltd.
19.44 MHz Osc. Troubleshoolting
VCTCXO
OUTPUT :
19.44 MHz
G850
P:>0.6Vpp
Change G850
N
Check
AFC–signal from
G850, pin1
V
≅
1.05 V
Note!
Check all solderings and supply voltage
for VCTCXO.
Check also coil L868.
Check resistor
R850
Check 2G PLL
N880, pin 15
P: >0.6 Vpp
Check capacitor
C851
Check
RFC–buffer
output, C719
P: >0.3 Vpp
Check L762 and
C745.
Check 3X tank
N750,C745,L762
P: >150 mVpp
N
Y
Y
N
Check EROTUS
OSC input,pin 24
P:>0.6Vpp
N
Start BB
troubleshooting
.
N
Y
Y
N
Change
EROTUS.
Start COBBA_D
trobleshooting
Y
Check
capasitor C883
Check EROTUS
supply voltages
Y
Y
Y
N