Nokia 6088 Guide

Nokia Customer Care
6088 (RM-218)
Mobile Terminal
RF Description and
Troubleshooting
Issue 1 10/2006 Company Confidential ©2006 Nokia Corporation

6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
Contents Page
Component Layout ................................................................................................... 3
Tx Troubleshooting................................................................................................... 5
Tx system block diagram ...................................................................................5
Tx introduction ...................................................................................................6
Main TX component...........................................................................................6
FTM setup for TX troubleshooting......................................................................7
TX DC Test Points..............................................................................................8
Tx RF Test Points...............................................................................................9
Tx DC Test Points ............................................................................................10
Tx path troubleshooting ................................................................................... 11
Rx Troubleshooting ................................................................................................ 12
Rx system block diagram.................................................................................12
Rx introduction.................................................................................................13
Main RX component ........................................................................................13
FTM setup for RX troubleshooting ...................................................................13
Cell Receiver Check from RF to IQ..................................................................14
Receiver DC Test Points..................................................................................16
Receiver RF Test Points ..................................................................................17
Rx path troubleshooting...................................................................................18
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
Component Layout
Figure 1 shows the main components of the 6088 mobile terminal.
Power Mana
g
ement IC
Rx Saw filter
RF Receiver
RFAntenna
Direction Coupler
Tx Saw filter
Power Amplifier Cell Duplexer
RF Transmitter
Power Detector
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
RF Connector
19.2MHz TCXO
132.768KHz
Cr
y
stal
Figure 1: Component layout
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
Tx Troubleshooting
Tx system block diagram
Figure 2: Tx system block diagram
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
ntial Page 6
Tx introduction
The RFT6122 (Figure 2) provides the Zero-IF transmit signal path for Cellular-CDMA transmission. For this chipset, Cellular-CDMA refers to
band classes 0 and 3 as defined by the cdma2000 standard, with mobile station transmitters operating between 824 and 925 MHz. The
transmit signal path includes baseband amplifiers, quadrature upconversion, gain control RF amplification, and an output driver amplifier.
The driver amplifier output is routed to the final stages of the transmit chain – power amplifier, isolator, duplexer, and antenna.
Main TX component
TX Saw filter
Power Amplifier
Direction coupler
Power detector
TX IC
Cell Duplexer
Figure 3: Tx components
Issue 1 10/2006 ©2006 Nokia Corporation Company Confide

6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
FTM setup for TX troubleshooting
Put PWB on the module jig. Use the following steps to configure FTM for RF
troubleshooting.
1. Select “FTM mode” in Module Jig
2. Connect RF connector to a spectrum by using CA-89RS RF Test Cable
3. Connect 6088 mobile terminal to a PC via Module Jig, and connect power
supply to Module Jig
4. Open RF Tools software in 6088 CCS Level 3 service software
5. The FTM dialog box appears
6. Set COM port to appropriate one in “Select COM port”
7. Set “Connect Phone”
8. Set “Set FTM”
9. Set “Set Band” to “CDMA800”.
10. Set “Set Channel “ to Channel “384”
11. Set “Set Pa Range R1” to “on”
12. Set “Set TX waveform” to “CDMA”
13. Set “Set TX on/off” to “on”
14. Set “Set TX AGC” to “100”
Figure 4: FTM dialog box
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
TX DC Test Points
6
1
2
4
5 U631pin8
3
Figure 5: Tx DC test point
8
7
Table 1: Tx DC Test Points
Test Point Description Value
1 PA_ON 2.86V for PA turning on, 0 V for turning off
2 PA_R1 1.97V for high gain mode,1.38V for low gain mode
3 LOCK_DET 2.95V for Lock, 0 V for unlock
4 TX_AGC 1.86V for 5dBm, 2.12V for 15dBm, 2.38V for
25dBm.
5 Tx IQ in 0.84 V With oscilloscope: 500 mV p-p
6 DAC_REF 1.56V
7 VREG_MSMP 2.96V
8 VREG_RFTX 2.64V
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
Tx RF Test Points
4
Figure 6: Tx RF Test Points
Table 2 shows the test points shown in Figure 6.
Test Point Description Value
1 RFT6122 output 3dBm
2 PA input 1dBm
3 PA output 27dBm
4 RF connector 24.5dBm
5 UHF LO 0dBm at 1763.04MHz
5
3
1
2
Table 2: Tx RF Test Points
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6088 (RM-218)
Nokia Customer Care RF Description and Troubleshooting
Tx DC Test Points
7
6
5
8
3
1
1
4
2
Figure 7: Bottom side Tx DC test points
Table 3 shows the Tx DC test points shown in Figure 7.
Test
Point Description Value RF Supply Lines Resistance to Ground
1 VREG_MSMP,C861 2.96V >11kΩto ground U632,U631,U629,U1
2 VPH_PWR,C854 3.2~4.2V >550kΩto ground U632,U7
3 VREG_MSMC,C860
1.91V >45kΩto ground U632,U625
4 VREG_MSMA,C858
2.62V >120kΩto ground U632,U625
5 VEXT_DC,R840 3.2~5.7V ~9.3kΩto ground Q400
6 VREG_TCXO,C857
2.82V >450kΩto ground U632
7 VREG_RFRX,R855
2.66V >350kΩto ground U632,U631,U629
8 VREG_RFTX,C856
2.64V >450kΩto ground U632,U631,U629
Table 3: Tx DC Test Points and RF Supply Line Resistance to Ground
*Note: Always measure resistance with the phone powered off
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