
NPM-10
Troubleshooting Instructions RF
CCS Technical Documentation
Page 28
Nokia Corporation Confidential
Issue 1 03/2003
Troubleshooting chart for PCS transmitter
Figure 20: GSM1900 transmitter troubleshooting chart
Figure 21: VPCTRL_P
** TXIQ signals look the same in PCS and GSM
PCS 1900 band, Power level 0, Channel 661
Black trace:Vpctrl_P @ R708 output
Measure Power
on ANT with
Power Meter
or RCT
> 28 dBm
Measure
TX Power
on PCS-TX.
Power ~ 28 dBm
Measure
Pout_DCS
29 dBm
Measure
Pin_PCS
-2 dBm
Measure
OUT_D_TX
Buffer input
-3 dBm
Measure BAL
input to T600
-4 dBm
With Scope
check :
VTX= 2.7V +
discretes around
No
No
No
No
No
No
Yes
With Scope check
Ant. switch:
Vcon2_DCS = 2.7 V
Vcon1_GSM = 2.7 V
Check R759,
L702
Check Z700
( Ant. switch )
Yes
Check L709
( Coupler )
Yes
With Scope
check :
VPCTRL_P
( See figure 21 )
Yes
Check N700
( PA )
Yes
With Scope
check :
VTX_B_P = 2.7
V
Yes
Check V701
+
discretes around
Yes
Check T602
( PCS Balun)
Yes
Check TXIP and
TXQP
( See figure 19 )
Yes
Check
Base band
Yes
With Scope
check :
TXC
( See figure 21 )
NO
Check V700
( detector )
+
discretes around
Yes
Check Mjolner
+
the serial bus
NO
NO
NO
NO
NO
Yes