St Robin Vhf Pll Pcs; Sn Cell Pa Temp - Nokia NPD-4 Series Technical Documentation Manual

CCS Technical Documentation
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
TX_RF_AGC to -512
PA_AGC to -512.
(2) TX_IF_AGC to +511
TX_RF_AGC to -512
PA_AGC to +511
(3) TX_IF_AGC to -80
TX_RF_AGC to +511
PA_AGC to +511
Troubleshooting: If there is a failure associated with only some of the cases above, check
the AGC voltages and components of the associated PDMs as described in Tables 1 and 5.
For problems with the IF or RF AGC, also check Robin and supporting components. For PA
AGC problems, also check the PA and supporting components. If all of the above cases
fail, troubleshoot the TX chain as described in the Probing Diagrams section. If all the
output powers are passing, then perhaps the test is failing because the ADC voltage is
wrong (which at this point we cannot read, so we are measuring the actual output
power). This can be verified by measuring the voltage on the PWROUT, at probing point
48 in Figure 10. The limit is 1.09 v. If the voltages are wrong, then check the power
detector at R801, R803, L801, and N806, and also Robin. If the voltages are correct and it
still fails, check the UEM (D200).

ST Robin VHF PLL PCS

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 PCS CDMA Rx/Tx to any channel and probe at L611
(probing point 11a in Figure 5) using an RF probe connected to a spectrum analyzer
tuned to 416.2 MHz. If the PLL is locked, it will be stable in frequency. If it is unlocked,
you may have to use a wide span so see it since it may be far off frequency.
Troubleshooting: First check that V610 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.

SN Cell PA Temp

This is one of the phone's self tunings, which reads the ADC voltage of a thermistor
R808, and checks to make sure the phone is at room temperature. The reason for this is
that we don't want to tune a phone while it's hot or cold.
The phone reports the ADC voltage value of the thermistor, and it should be within the
Issue 1 02/2003
Nokia Corporation
Troubleshooting — RF
Confidential
NPD-4
Page 11