User Guide

PAMS
Technical Documentation
NHD–4
Disassembly & Troubleshooting
Page 52
Original 11/97
For CDMA TX operation above the switchpoint, the TX_ICT current will be
at its maximum, approximately 1.0 mA. There should be approximately
100 mV of voltage drop across R116.
For more information on the Auxiliary AGC control feature, consult section
3.4.3.2 of this document.
CDMA RX Gain Control Test
To test the gain control abilities of the CDAGCR IC (N1) do the following:
3. Place the phone in the CDMA Troubleshooting Mode
4. Use the CDMA RX manual gain control found in the Service
Software to adjust the CDMA receiver gain.
5. Verify the RX_IREF current signal as the voltage drop across
R17. The voltage drop should be approximately 350 mV.
6. Observe the RX_Gain voltage at C213 and the RX_ICT current
as a voltage drop across R16. The table below details approximate
values that should be read.
CDMA RX RF Signal
Level
(dBm)
RX_GAIN Voltage
at C213
(V)
RX_ICT Control
Current
(mA)
RX_ICT
(as voltage drop
across R16)
(mV)
–25 2.06 0.020 7
–45 2.00 0.033 11
–65 1.91 0.073 24
–85 1.82 0.158 52
–105 1.73 0.278 92
AMPS TX Gain Control Test
The AMPS transmitter gain is controlled from the TXI_REF PDM. This
PDM has a manual control within the AMPS Quick Checks window of the
Service Software Test menu. With the phone in AMPS Troubleshooting
Mode the transmitter output power can be manipulated with this PDM
control. The table below details approximate PDM values, in decimal,
necessary to achieve corresponding power levels. These values will vary
from phone to phone.
AMPS TX
Output Power (dBm)
TXI_REF PDM
decimal value
30 00
27 238
24 208
21 176
18 166
15 160
12 155
9 152
6 151