Nokia Customer Care
Appendix A: RF Troubleshooting
A-84
Company Confidential
Copyright
©
2005 Nokia. All rights reserved
explained in section “Transmitter troubleshooting”.
•
Measurements can be done with a spectrum analyser and an RF probe. Spectrum analyser RBW =
VBW = 10 MHz, Span
≤
2 MHz, sweep time 100 ms. Spectrum analyser centre frequency should be
set according the used TX channel (see section “Frequency mappings”).
•
Connect the RF probe to R7520. The RF-level should be about the same on both ends of the
resistor. Check output level with 0 dBm (“0”) power level.
-
Power level (“0”) – Output level should be about -45…-48 dBm
•
Check if output levels of Vinku are as expected.
4.1.2.1.1 RF operating voltage VBAT_ASIC ok?
•
See section
“RF operating voltage VBAT_ASIC ok?”
4.1.2.1.2 Vinku (N7501) regulator voltages VREG1, VREG2 ok?
•
WCDMA transmitter has to be active before VREG1 and VREG2 voltages can be measured. Procedure
is explained in section “Transmitter troubleshooting”. Measurements can be done with an
oscilloscope and a probe.
•
VREG1: Connect the probe to C7543
•
VREG2: Connect the probe to C7548 (or C7547)
•
VREG1 and VREG2 voltage levels should be 2.65 – 2.86 V. Typical value is 2.7 V.
4.1.2.1.2.1 Vinku (N7501) RB_EXT voltage ok?
•
WCDMA transmitter has to be active before Vinku’s RB_EXT voltage can be measured. Procedure is
explained in section “Transmitter troubleshooting”.
•
Measurement can be done with an oscilloscope and a probe.
•
Connect the probe to R7521.
•
RB_EXT voltage should be 1.325 – 1.375 V.
4.1.2.1.2.1.1 VREFRF01-voltage ok?
•
Measurement can be done with an oscilloscope and a probe.
•
Connect the probe to R7503.
•
VREFRF01 voltage should be 1.325 – 1.375 V. Typical value is 1.35 V.
4.1.2.1.2.1.1.1 Desolder R7503. Is VREFRF01 voltage still wrong?
•
Remember to solder a new component to R7503 pads after measurement.
4.1.2.1.2.1.1.1.1 Capacitors C7518, C7520 and C7570 working correctly?