Afc Voltage Troubleshooting - Nokia 6275 Rf Description And Troubleshooting

6275/6275i (RM-154)
RF Description and Troubleshooting
VCTCXO 19.2MHz clocks:
-9 dBm to UHF PLL
CLK19M2_TIKU to BB
F_REF_RX to RX back-end IC
F_REF_TX to TX IC
F_REF_TX to Bluetooth
VPLL: 2.7V VR1A: 4.7 V

AFC Voltage Troubleshooting

Use the following steps to monitor the AFC voltage.
1. In Phoenix, open the RF PDM dialog box.
Page 38
Lock voltage:
DC between 0.8 and 3.4 V,
S/B 1.2V at center frequency
VR4: 2.7 V
VR3: 2.7 V
Figure 32: VCTCXO and UHF Synthesizer test points
Figure 33: RF PDM dialog box for AFC troubleshooting
Company Confidential
AFC voltage:
DC between 1 and 3 V
1.3V for PDM 0
0.8 V for PDM -1024
2.5 V for PDM 1023
Dual-band VCO
UHF LO:
PCS_CEL_LO input to RX front-end IC
Cell CH384: 1009.62MHz > -9 dBm
PCS CH600: 2088.1MHz > -16 dBm
Issue 1 - September 2006
BAND_SEL_VCO
Cell 0 VDC
PCS 2.7 VDC
PCS_SEL_LO
return to UHF PLL
Cell -11 dBm
PCS -18 dBm