Test Tx Start-Up Current; Test Tx Start-Up Amplitude; Tn Vctcxo Frequency - Nokia RH-10 Series Troubleshooting Manual

RH-10
Troubleshooting
The DC offset is returned for I (or Q).
Manual Verification: Using the "RF Tuning" dialog box in Phoenix, set mode to Self Tune,
and choose this tuning.
Troubleshooting: Check Batman (N701) and supporting components.

Test TX Start-up Current

This test turns on the AMPS transmitter (PCS transmitter for PCS-only phones) and mea-
sures current of the whole phone—which can detect some assembly errors.
Manual Verification: Set the phone to local mode and turn on the AMPS transmitter. Set
the PDM values as listed in Table 1a for AMPS Power Level 5 (for PCS, set output power
to +12dBm). Read the phone's current on the power supply and check to see that it is
within the set limits. If the power supply does not display current draw, use a current
meter in series with the phone. If the phone powers down when the mode is set, it may
be that the phone is drawing more current than the current limit setting on the power
supply.
Troubleshooting: If current is very high, there may be a short circuit on the phone caused
by a solder bridge, a failed component that is internally shorted, a component placed
with the wrong rotation, or some other reason. Short circuits can be difficult to find, but
one of the easiest methods is to use a thermal camera and look for hot spots that are not
normally hot. Look for the hottests spots. A visual inspection can find solder bridges or
wrong component rotations. A failed component can be found by functional tests of the
phone's sub-blocks.

Test TX Start-up Amplitude

This test turns on the AMPS transmitter and checks for the presence of a TX signal with
an amplitude within a specified range. A wide range is allowed since the transmitter is
not yet tuned.
Manual Verification: Set the phone to local mode and turn on the AMPS transmitter set
to channel 384. Set the AGC PDM values as in Test 17. Look for an output signal at
836.52 MHz with an amplitude within the set limits. The frequency of the signal may not
be accurate since the VCTCXO has not been tuned yet.
Troubleshooting: Check proper placement, rotation, and soldering of the components of
the TX chain, as shown in Figure 1. Check for the presence of LO tones as listed in
Table 2. Check for the presence of a TX signal at each point in the TX chain, probing
according to Table 2.

TN VCTCXO Frequency

The purpose of this tuning is to determine what the AFC DAC value needs to be in order
to center the VCTCXO frequency. The PCS transmitter is turned on and no TX baseband
modulation is provided. The carrier then is centered in frequency. This is done to the car-
rier after it has been mixed up to 1880 MHz, since it is easier to measure the tolerance of
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Nokia Corporation
CCS Technical Documentation
Confidential Issue 1 09/2002