Nokia 3570, 3585 Service Manual 8 npd1troubleRF
CCS Technical Documentation
NPD-1 Series Transceivers
Troubleshooting — RF
Issue 1 11/2002 Confidential Nokia Corporation
NPD-1
Troubleshooting — RF CCS Technical Documentation
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CCS Technical Documentation Troubleshooting — RF
Contents
Page No
RF Troubleshooting ....................................................................................................... 5
Tuning Descriptions....................................................................................................... 8
ST Batman VHFPLL ...................................................................................................8
ST TX Detector Cell ....................................................................................................9
ST Robin VHFPLL Cell ............................................................................................10
ST TX Detector PCS .................................................................................................10
ST Robin VHF PLL PCS ...........................................................................................11
SN Cell PA Temp ......................................................................................................11
SN Cell RX BB Filter ................................................................................................12
SN Cell RX DC Offset I (or Q) .................................................................................12
SN AMPS RX BB Filter ............................................................................................12
SN AMPS RX DC Offset I (or Q) .............................................................................13
Test TX Start up Current ...........................................................................................13
Test TX Start up Amplitude ......................................................................................13
TN VCTCXO Frequency ..........................................................................................13
TN TX DC Offset Reference Power ..........................................................................15
TN TX DC Offset Carrier Suppression .....................................................................16
TN TX IF AGC Cell Po (0) [or (1), (2), (3), or (4)] ...............................................17
TN PA Gain Cal Cell Po (0) [or, (1), (2), (3), (4), or (5)] ......................................18
TX TX IF 11 dBm Set CELL Po ...............................................................................19
TN TX RF AGC Cell Po (0) [or (1), or (2)] ...........................................................19
TN TX Gain Comp Cell (or PCS) Po MD (or LO, LM, ML, MH, HM, or HI) ........20
TN G_Offset Cell MD ...............................................................................................21
TN AMPS PL2 Po Mid (or Low, LowMid, MidLow, MidHigh, HighMid, or High) 21
TN AMPS PL3 (or 4, 5, 6, or 7) Po ...........................................................................22
TN PA Gain Cal PCS Po (0) [or (1), (2), (3), (4), or (5)] .......................................22
TN TX IF 11 dBm Set PCS Po ..................................................................................22
TN TX RF AGC PCS Po (0) [or (1), or (2)] ...........................................................22
TN TX Limiting Po Cell (or PCS) IS95, Low channel (or LowMid, MidLow, Mid,
MidHigh, HighMid, or High channel) .....................................................................23
TN TX Limiting Cell (or PCS) CDMA2000: Po ......................................................23
TS ACPR PCS- Low (High) ......................................................................................24
TN PA Detector PCS Po (0) [or (1), (2), (3), (4), (5), (6), or (7)] .........................25
TS ACPR Cell - Low .................................................................................................26
TN RX IF AGC RXdBCtr (0) [or (1) or (2)] ..........................................................26
TN LNA AMPS (or Cell or PCS) LowGain (or HighGain) LO (or LM, ML, MD,
MH, HM, HI) ...........................................................................................................27
Final UI test: Rho .......................................................................................................27
Final UI test: Frame Error Rate (FER) ......................................................................28
Final UI test: SINAD .................................................................................................28
Probing/Troubleshooting Tables and Diagrams .......................................................... 28
Transmitter Probing................................................................................................. 29
Receiver Probing..................................................................................................... 34
RF Power Supplies.................................................................................................. 40
Probing Diagrams ................................................................................................... 41
APPENDIX A: Phoenix Instructions........................................................................... 45
To turn on the PCS or Cell CDMA transmitter....................................................... 45
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To turn on the AMPS transmitter............................................................................ 46
To turn on the receiver only, in any mode .............................................................. 48
To verify a single, manual tuning............................................................................ 48
To adjust PDM values of AGCs and AFC.............................................................. 48
To read tuning values from the phone..................................................................... 49
To read RSSI and AGC PDM values from the phone............................................. 49
To load a PRL into the phone.................................................................................. 50
To change between Local and Normal modes ........................................................ 50
To add a baseband test tone to the AMPS transmitter............................................ 51
APPENDIX B: Definitions.......................................................................................... 52
APPENDIX C: Block Diagrams.................................................................................. 53
APPENDIX D:
Descriptions of selected components, signaling, and architecture ........................ 58
Robin (N601) Key Features .................................................................................... 58
Robin (N601) Signaling.......................................................................................... 58
Batman (N701) Key Features.................................................................................. 59
Batman (N701) Signaling........................................................................................ 60
PA Key Features: Shark (N801, Cell) and Snapper (N802, PCS) .......................... 60
LNA/Downconverter (N750) Key Features............................................................ 60
APPENDIX E: AGC Algorithms................................................................................. 61
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RF Troubleshooting
If TX power is low, turn on transmitter in local mode using Phoenix. Check:
• current (0.7 – 1 A for max power, mode and channel dependent.)
• perform visual inspection of PWB under microscope to check proper
placement, rotation, and soldering of components
• Look for presence of TX signal on spectrum analyzer at the correct frequency. If signal is n ot on frequen cy, check in 100 MHz span . If signal is
present but off frequency, check synthesizer. If signal is not present, or
present but low in amplitude, use probing Tables 1 through 5 to determine where in the chain the fa ult occur s, wi th AG C PD Ms set for know n
transmit power as listed in Table 1
• Check that AGC PDMs are set for desired TX power according to
Tables 1 and 3, and ensure that AGC voltages are correct
• according to Tables 2 (cell/AMPS) and 4 (PCS), check the LOs for
proper frequency and amplitude
• ensure power supplies to transmitter have correct voltage, as per
Table 12
If Receiver is not working properly, turn on transmitter in local mode and check:
• turn on receiver with Phoenix, inject a signal into the receiver
• check the RSSI level and AGC PDM according to Table 6
• perform a visual inspection of the PWB under a microscope to check
proper placement, rotation, and so ldering of components
• use probing Tables 6 through 11 to measure signal levels at various
points in the chain and determine where in the chain the fault lies
• according to tables 3a through 4b, check the LOs for proper frequency
and amplitude
• ensure power supplies to receiver have correct voltage as per Table 5
If phone won’t make a call:
• ensure phone is in n orm al mod e ( i.e., ensure t he ph one i s sea rchin g for
a signal, i.e., net server is on).
• ensure Preferred Roaming List (PRL) is loaded into phone
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• ensure phone is tuned (read tuning parameters using Batch Tune component in Phoenix, an untuned phone will have all zeros in tuning file),
and has passed tuning
• ensure call box channel is set for a channel in PRL, and ensure SID is
correct
• ensure MIN, MDN, and SID are entered into the phone
• ensure VCTCXO is centered, as described in VCTCXO tuning description below
• ensure transmitter and receiver are working properly by checking them
in local mode.
To troubleshoot the antenna circuits, refer to document DHK00086-EN by Tim Mcgaf-
figan.
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Figure 1: Eagle PWB bottom (general placement)
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Figure 2: Eagle PWB top (general placement)
Tuning Descriptions
NOTE: Pass/Fail limits are not provided in this document as they may be changed.
ST Batman VHFPLL
This is one of the phone’s self tests, which gives either a “pass” or “fail” result only. The
VHFPLL is inside the Batman 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 or PCS receiver to any channel and probe at L701
(probing point 39 in Figure 6) using an RF probe connected to a spectrum analyzer tuned
to 256.2 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 V701 has the proper orientation, then check C701,
C714, R703, R702, C715, R704, C716, L701, and C702. Also check power supplies to Batman, particularly check for 2.7v on VR5 at C710, and on VR7 at C708, and check for 1.8v
on VIO. If no fault is found, replace N701 (Batman).
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ST TX Detector Cell
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 Cell CDMA TX with channel set to 384, and turn on IS95
modulation using CDMA control.
Using the PDM window, set:
TX_IF_AGC to – 100
TX_RF_AGC to –512
PA_AGC to +511.
Record the TX signal power from the antenna connector using a spectrum analyzer centered at 836.52 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
functionality without removing the covers is to check transmitted power. If the covers
are removed, the voltage on PWR_OUT, at probing point 48 in Figure 1, can be measured). Transmitted power should be greater than 24 dBm. (PWR_OUT greater than 1.91v,
which corresponds to the power detector ADC=700).
For each of the next three cases, TX power should be less than 24 dBm (less than 1.91v
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 3.
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 probing point 48
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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 modulation 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 centered 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 functionality 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
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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 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 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 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 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
limits.
Manual Verification: Ensure the phone is cool by letting it cool down for several minutes,
and retest, keeping in mind that if there is a short circuit on the board, then it will get
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hot very quickly.
Troubleshooting: If the phone was recently transmitting in Cell band at full power for an
extended period of time, it is probably hot for that reason. Let it cool down for a few
minutes, then try again. If it still fails, there may either be a short on the board or else a
problem with the PA Temp circuitry. To check PA Temp circuitry, check R808, C232,
R202, and D200. If a short is suspected, check the cell PA first. If an infrared camera is
available, this is one of the easiest methods to detect a short.
SN Cell RX BB Filter
This is one of the phone’s self tunings, which tunes the lowpass filter in the Batman IC
N701, in cell CDMA mode.
This self tuning returns one of the filters tuned parameters, which should be within the
limits.
Manual Verification: Use RF Tuning window in Phoenix, set mode to “self tune” and
choose this tuning.
Troubleshooting: Check Batman (N701) and supporting components.
SN Cell RX DC Offset I (or Q)
This is one of the phone’s self tunings, which measures and adjusts the cell band CDMA
receiver DC offsets until they are within the limits.
The DC offset is returned for I (or Q).
Manual Verification: Use RF Tuning window in Phoenix, set mode to “self tune” and
choose this tuning.
Troubleshooting: Check Batman (N701) and supporting components.
SN AMPS RX BB Filter
This is one of the phone’s self tunings, which tunes the lowpass filter in the Batman IC
(N701) in AMPS mode.
This self tuning returns one of the filters tuned parameters, which should be within the
limits.
Manual Verification: Use RF Tuning window in Phoenix, set mode to “self tune” and
choose this tuning.
Troubleshooting: Check Batman (N701) and supporting components.
SN AMPS RX DC Offset I (or Q)
This is one of the phone’s self tunings which measures and adjusts the cell band AMPS
receiver DC offsets until they are within the limits.
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The DC offset is returned for I (or Q).
Manual Verification: Use RF Tuning window 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 measures 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 1 for AMPS Power Level 5 (for PCS, set output power to
+12 dBm). Read the phone’s current on the power supply and check to see that it is
within the 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 (which shorts two nodes that shouldn’t be), 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, and look for the hottest
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 (PCS transmitter in PCS-only phones) 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 limits. The frequency of the signal may not be
accurate since the VCTCXO has not yet been tuned.
Troubleshooting: Check proper placement, rotation, and soldering of the components in
the TX chain, as shown in Figure 5. Check for the presence of LO tones as listed in
Table 2. Check for 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 is then centered in frequency. This is done to the carrier after it has been mixed up to 1880 MHz, since it’s easier to measure the tolerance of
1 ppm at 1880 MHz than it is at 19.2 MHz. Additionally the tone at 1880 MHz can be
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measured without taking the phone apart.
The result is a PDM value for the AFC DAC, which must be within +/- 150, which corresponds to 2.2 v on the VCTCXO control pin (pin 1) and the carrier centered within
+/- 100Hz. The VCTCXO must be able to be centered within a certain voltage range in
order to allow for aging of the crystal (the centering voltage slowly drifts over time and
the phone will eventually run out of voltage range if it begins too close to the edge of
the range).
Manual Verification: Using the RF Main Mode window in Phoenix, turn on the PCS transmitter, and set it to channel 600. Do not add any modulation.
Using the RF Tuning window, set mode=RF Tuning and choose this tuning. Look for a
transmitted tone on the spectrum analyzer at 1880 MHz. If no tone is present, proceed
to Troubleshooting section.
Center the carrier to within +/- 100 Hz of 1880 MHz. (If sidetones are present, be careful
to center the carrier and not one of the sidetones, which will probably have a higher
amplitude than the carrier.) The values you enter in the “values” edit box are the AFC values which control the VCTCXO frequency. Start with a value of 0, then adjust until it is
centered, staying within the limits.
Troubleshooting:
1) If there is no tone, probe pin 3 of G501 for a tone at 19.2 MHz. If this is not present
check power supplies, particularly ensure 2.7v on VCTCXO Vcc pin, pin 4 of G501. Also
check the control pin, pin 1 of G501, for a voltage between 0.4 and 2.7 v. If the voltages
are correct, and soldering of all G501 terminals is correct, replace G501. If 19.2 MHz tone
is present but tone at 1880 MHz is not, troubleshoot PCS TX chain as described in the
Probing Diagrams section.
2) If the carrier is present but the PDM needed to center it is outside of the +/- 150
range, or if it cannot be centered, there is a hardware problem.
3) In the following procedure, performing frequency centering on the RF carrier at
1880 MHz will detect frequency errors due to the VCTCXO and supporting hardware,
which will be the majority of the problems, but will not detect frequency errors due to
the hardware that mixes the VCTCXO tone at 19.2 MHz up to 1880 MHz. In order to
troubleshoot this hardware also, frequency centering should be performed on the
19.2 MHz tone to +/- 19.2 Hz on pin 3 of G501 using a frequency counter, then the VHF
and UHF LOs should be checked. Since this will be time-consuming and will probably
only account for a small percentage of the failures, it is not recommended unless the situation justifies the time spent. The VHF LO is inside the Robin IC (N601) and troubleshooting of the cell UHF LO is according to Table 2.
4) If the carrier can be centered but the PDM is out of range, check the control voltage
on pin 1 of G501. If it is 2.2v, (and pin 4 is at 2.7v, and pin 2 at 0v), then the VCTCXO
(G501) is working correctly but the circuit that delivers the control voltage is not. Check
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soldering of all G501 terminals; also check R510, R511, C503, and D200. If the control
voltage on pin 1 of G501 is not 2.2v, but the carrier is centered, then there is a problem
with the VCTCXO G501. If there is 2.7v on pin 4 and the soldering is correct, then replace
G501.
5) If the carrier cannot be centered, check to see if you can adjust to 2.2v on pin 1 of
G501. If you can, within the PDM range of +/- 150, then the circuitry that delivers the
voltage is working correctly, and the VCTCXO has a problem. Troubleshoot it as described
in the previous section. If you cannot adjust to 2.2v within the accepted range, then the
AFC circuitry has a problem. Troubleshoot it as described in the previous section.
6) In cases where there is a fault with both the AFC circuitry and the VCTCXO, several
combinations of the previously described conditions are possible. Start by ensuring 2.2v
on pin 1 of G501 using a PDM within the range +/- 150, then center the tone.
TN TX DC Offset Reference Power
The DC offset voltages on the I and Q inputs to the modulator are adjusted for minimal
carrier feedthrough (maximum carrier suppression). Initially the DC offsets are set to a
nominal value, and the power of a tone offset in frequency 20 kHz from the carrier is
measured in dBm and recorded as a reference (in this tuning). Then in the next tuning,
the carrier suppression (delta between center tone and tone that is offset 20 kHz) is
measured. If it passes, it is reported in that tuning. If not, the DC offsets are adjusted
until it passes, and the passing value is reported.
The reported result is the power in dBm of the tone that is offset 20 kHz from the carrier,
as measured on the antenna connector, with the nominal DC offsets applied.
Manual Verification:
In Phoenix, use the RF Main Mode window to set the AMPS transmitter to channel 384.
Using the RF Tuning window, set the I and Q DC offsets to 0,0 by entering 0,0 in the “values” edit box.
Center the transmit signal on the spectrum analyzer, set the span to 100 kHz. Lower the
bandwidth so that the two sidetones can be differentiated from the carrier. Measure the
amplitude of the sidetone at 20 kHz above the carrier. The amplitude of the sidetone will
probably be higher than that of the carrier; amplitude should be within the test limits.
Troubleshooting: If the carrier is not present, troubleshoot the cell TX chain using the
“things to check” list and probing tables/diagrams. If the two tones offset at 20 kHz are
not present on the TX signal, check to see if they are on Robin output at L613 at
836.52 MHz + 20 kHz. If not, there is likely a problem with N601 (Robin). Ensure power
supplies to Robin (VR2, VR3, VR6, and VIO) are correct. Check components around Robin.
If still failing, replace Robin.
TN TX DC Offset Carrier Suppression
See previous tuning. This step reports the delta between the reference at 836.52 MHz
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+ 20 kHz, and the minimum carrier level at 836.52 MHz.
The result is a delta in dB between the reference at 836.52 MHz + 20 kHz, and the minimum carrier level at 836.52 MHz, found by adjusting the DC offsets for I and Q individually. The delta should be at least 35 dB.
Manual Verification: Set up the phone as in the previous test, and record the reference
power of the offset tone. Measure the delta between the center and offset tones. If the
delta is 35 dB or greater, the phone passes. If less than 35 dB, vary the “I“ DC offset on
the “values” line in the RF Tuning window, using the below listed values until the minimum carrier maximum delta is found. Leave Q at 0. On the “values” line, you enter “I,Q”.
The values, in decimal, are:
-560
-504
-448
-392
-336
-280
-224
-168
-112
-56
56
112
168
224
280
336
0
392
448
504
560
If the minimum is 35 dB or greater, the phone passes. If the minimum is less than 35 dB,
then vary Q in the same manner as I using the above values, holding I constant at the
minimum value determined above, until the delta is at least 35 dB.
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Troubleshooting: Check N601 (Robin), D200 (UEM), and associated components.
TN TX IF AGC Cell Po (0) [or (1), (2), (3), or (4)]
The IF gain curve is characterized by varying the TX_IF_AGC and measuring the transmit
power. This is only done once (in cell CDMA mode) since the same circuitry is used for
both cell and pcs.
The results are TX power readings in dBm of the transmitted signal corresponding to
given PDM settings of the Cell TX IF AGC.
Manual Verification:
Set the phone in local mode, then program it to Cell CDMA RX/TX mode on channel 384.
Set modulation to IS95 voice.
Set the Cell PA PDM to +218 decimal and the TX RF AGC to –512 decimal using the sliders in the PDM window under the RF menu.
Change the TX_IF_AGC to the settings in the following table, and measure the TX power
levels, checking to see that they are within the specified range.
PDM for TX IF AGC
(a) +300 decimal check tuning results file for limits
(b) + 150
(c) 0
Acceptable range for output
power (in dBm)
Change the TX_RF_AGC PDM to +511. Leave the TX_IF_AGC at 0 and the PA_AGC at
+218. Measure the output power. Subtract this power from the power measured in (c) in
the table above. This is the RF_AGC gain delta.
Leave the PA_AGC and TX_RF_AGC values as is, then enter the values listed below for
the TX_IF_AGC. Measure the output power, then add to each the RF_AGC gain delta calculated above. Check that these sums are within the listed ranges.
Acceptable range for
PDM for TX IF AGC
sum:[output power +- RF_AGC
gain delta] in dBm
-200 check tuning results file for limits
-400
Troubleshooting: Check Robin (N801) and supporting components. Also check D400,
which generates the PDM signals. Check AGC PDM voltages according to Tables 1 and 3.
Troubleshoot the rest of the transmitter chain if necessary as described in Table 2.
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Troubleshooting — RF CCS Technical Documentation
TN PA Gain Cal Cell Po (0) [or, (1), (2), (3), (4), or (5)]
These tunings model the cell PA gain curve by setting the PA AGC PDM to several values
and measuring output power. First, the TX PA AGC and the TX RF AGC are set to (approximately) their maximum used values (not the maximum possible values, but the maximum of the range over which they are used). Then the TX IF AGC is set so that the
transmit power on the antenna connector is approximately +11 dBm (this power is
reported in the next tuning). Then, six PDM values are written to the PA AGC and the
output power is measured for each. These values are reported in this tuning. The software then performs curve fitting to interpolate between the measured data points.
The result is the transmitted power in dBm for each of the six PA AGC PDM settings
(results labeled 0 through 5).
Manual Verification:
Turn on the cell CDMA transmitter in Phoenix using the RF Main Mode window, and set
it to channel 384. Set modulation to IS95 voice.
Set the TX_IF_AGC PDM to 0 decimal.
Set the PA AGC PDM to +218 decimal.
Set the TX RF AGC PDM to –512 decimal.
Adjust the TX IF AGC PDM so that the transmitted tone at 836.52 MHz measures
+11 dBm +/- 0.5 dB on the antenna connector, using a spectrum analyzer (use 0 as a
starting point). Make a note of this value as it is needed in other Troubleshooting sections.
Write the PDM values listed below into the PA AGC and record the output power. Check
to see if the output power is within the ranges listed on the tuning result printout. (Limits are not provided in this document as they may change.)
PDM for PA AGC
+218 decimal limit range for Po(5)
-12 limit range for Po(4)
-202 limit range for Po(3)
Acceptable range for output
power (in dBm)
-268 limit range for Po(2)
-329 limit range for Po(1)
Troubleshooting: If the power readings are low, check the AGC voltages as in Tables 1
and 3. You can also probe on the PA input as in Table 2 to find out if the power level is
low going into the PA, or if the power level is correct going into the PA but the PA gain is
too low. If the power level going into the PA is too low, probe the TX chain at all the
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CCS Techni cal Documentation Troubleshooting — RF
other points prior to the PA listed in the table to see where the gain is lacking. When
that point is identified, check the soldering of all related components, and replace components until the fault is found. If the power on the PA input is not low and the PA AGC
voltage is correct, similarly probe the power at all points after the PA to find the fault,
being extremely careful not to short the probing point to ground because this will
instantly destroy the PA. Visually check soldering first, and probe on PA output as a last
resort.
TX TX IF 11 dBm Set CELL Po
See previous tuning. This is the part of the previous tuning when the TX IF AGC is
adjusted so that the output power is +11 dBm
The result is a power in dBm. A perfect result would be +11.00 dBm.
Manual Verification: See previous tuning.
Troubleshooting: See previous tuning.
TN TX RF AGC Cell Po (0) [or (1), or (2)]
This tuning characterizes the RF AGC curve by entering PDM values to the RF AGC and
measuring the output power.
The results are TX power readings in dBm of the transmitted signal measured for each of
the listed PDM settings of the Cell TX RF AGC.
Manual Verification:
Turn on the cell CDMA transmitter in Phoenix using the RF Main Mode window, and set
it to channel 384. Set modulation to IS95 voice.
Set the Cell PA PDM to –329.
Set the TX_IF_AGC to the value determined in tuning TX TX IF 11 dBm Set CELL Po (above
section) to give +11 dBm on the output.
Change the TX RF AGC to the settings in the following table, and measure the TX power
levels, checking to see that they are within the specified range.
Issue 1 11/2002 Nokia Corporation Confidential Page 19
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