St Robin Vhfpll Cell; Sn Cell Pa Temp - Nokia RH-10 Series Troubleshooting Manual

RH-10
Troubleshooting
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 4.
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 the above cases fail,
troubleshoot the TX chain as described in this section.
If all the output powers pass, perhaps the test is failing because the ADC voltage is
wrong. The limit is 1.64v. If the voltages are wrong, then check the power detector at
R821, R801, R804, L801, C805, R806, R805, C803, V801, C804, 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 11, Figure 1), 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 space to see it since it may be far off frequency.
Troubleshooting: Check C612, C613, R607, R605, C632, R606, C638, L611, C631, C630,
V601, C629, V602, C637, R609, C618. Check power supplies to N601 (Robin), ensuring
2.7v on VR3 and VR6, and 1.8v on VIO. 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 thermistor R808,
and checks to make sure the phone is at room temperature. A phone should not be tuned
while it is either hot or cold.
The phone reports the ADC voltage value of the thermistor and it should be within the
set limits.
Manual Verification: Ensure the phone is cool by letting it cool down for several minutes.
Retest, keeping in mind that if there is a short circuit on the board, the phone will get
Page 6
Nokia Corporation
CCS Technical Documentation
Confidential Issue 1 09/2002