PAMS
Technical Documentation
NSC/W–1/3
Disassembly & Troubleshooting Instructions
Page 28
Original 11/99
Transmitter Fault AMPS
Check current
consumption:
I: >800 mA
AMPS, PWL2, CH383
Y
N
Check Antenna Circuit
and Duplex filter
Press down PA–module
Inreasing current
consumption ?
Note!
Check all supply voltages and soldering
Check also N900 pin3 frequency and
input power. Should be > –10 dBm and
f = 997.68 MHz. If not start synth trouble
shooting (tx–local are missing)
Replace PA,
Check VAPC
V: >2.2V
Y
N
Check PA input PWR
P: > 0 dBm
Change PA
Y
Y
N
N
Check Band passfilter
insertion loss
(max. 4dB)
Check Z901, R907 and
C929
Y
N
Check TXC
V: >1.5 V
Y
Start Power control
troubleshooting
N
Change N902
Is TX driver input OK?
P: > –20 dBm
Y
N
check for eventual
delamination
Check COBBA
TXCDAC
(Baseband)
Delamination means that the chip has
loosened inside the package during
reflow.
In Amps mode PA pin 16 bias voltage
should be > 2,2V