Nokia 7600 - PA & Antenna Switch Troubleshooting

CCS Technical Documentation 6-Troubleshooting
Company Confidential NMM-3
Issue 1 (11/2003) Copyright  2003 Nokia Corporation Page 6-19
Company Confidential
PA and Antenna Switch Troubleshooting
Check with RF probe
+4dBm 900MHz
-4dBm 1800MHz
Check with oscilloscope:
Check Ant Switch
GSM VANT-2 = 2.6V pulse
GSM VANT-1 = 2.6V pulse
OK ?
Check VANT line components
L638/L639/C551/352
OK ?
Check with oscilloscope:
VBatt = 3.8V
VCC1 = VCC2 = VCC3 = 3.8V
VTXLO-G= 2.8V pulse (0V GSM1800)
VTXB-G= 2.8V pulsed (0V GSM1800)
VTXB-D= 2.8V pulsed (0V GSM900)
OK ?
Check components
around PA
OK ?
Replace faulty
component
Replace HELGO
Replace PA
Replace faulty
component
Replace ant.
switch
Yes
Yes
No
Yes
Yes
Yes
No
No
No
Yes
OK ?