St Robin Vhfpll Cell; St Tx Detector Pcs - Nokia NPD-1 Series Troubleshooting - Rf

NPD-1
Troubleshooting — RF
in Figure 10. The limit is 1.6v. If the voltages are wrong, check the power detector at
R821, R801, R804, L801, C805, R806, R805, C803, V801, C804, R803, and C807, and also
Robin. If the voltages are correct and it still fails, check the UEM D200.

ST Robin VHFPLL Cell

This is one of the phone's self tests which gives either a "pass" or "fail" result only. The
VHFPLL is inside the Robin IC. The phone checks the VHFPLL's lock detect bit. If this bit
indicates that the PLL is unlocked, the test will fail.
Manual Verification: Turn on the Cell CDMA receiver to any channel and probe at L611
(probing point 11a in Figure 5) using an RF probe connected to a spectrum analyzer
tuned to 346.2 MHz. If the PLL is locked, it will be stable in frequency. If it is unlocked,
you may have to use a wide span to see it since it may be far off frequency.
Troubleshooting: First check that V601 and V602 have the proper orientation, then check
C612, C613, R607, R605, C632, R606, C638, L611, C631, C630, C629, C637, R609, C618,
and R613. Check power supplies to N601 (Robin), and ensure there is 2.7v on VR3 and
VR6, and 1.8v on VIO (Table 12 and Figure 9). If no problems are found, replace Robin.

ST TX Detector PCS

This is one of the phone's self tests which gives either a "pass" or "fail" result only. The
phone transmits at several power levels and checks the ADC value of the power detector.
The ADC value is measured first for a set of AGC values, then each AGC value is changed
one at a time to make sure that the ADC changes as each AGC is changed individually.
Manual Verification:
Using Main Mode: Turn on the PCS CDMA TX with channel set to 600. Turn on IS95 mod-
ulation using CDMA control.
Using the PDM window, set:
TX_IF_AGC to –150
TX_RF_AGC to –512
PA_AGC to +511
Record the TX signal power from the antenna connector using a spectrum analyzer cen-
tered at 1880 MHz. (The selftest measures the power detector reading instead, but at the
present time this cannot be done with Phoenix; therefore, an easy way to check func-
tionality without removing the covers is to check power out. If the covers are removed,
the voltage on PWROUT, at probing point 48 in Figure 10, can be measured). Transmitted
power for the above case should be greater than 24 dBm. (PWR_OUT greater than 1.09v,
which corresponds to the power detector ADC=400).
For each of the next three cases, TX power should be less than 24 dBm (less than 1.09v
on PWR_OUT):
(1) TX_IF_AGC to – 80
Page 10
Nokia Corporation
CCS Technical Documentation
Confidential Issue 1 11/2002