Nokia RM-57, Руководство по обслуживанию

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Appendix A: RF Troubleshooting Nokia Customer Care
Company Confidential
Copyright © 2005 Nokia. All rights reserved
A-50
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RX Q (negative): Connect the probe to test point J7511
• The correct RX IQ-signal is shown in figure 6.5.6 "GSM RX IQ (DC Offset 0.4 V)" . Level of all four
IQ-signals should be about the same and RX IQ-signal frequency should be 67.71 kHz (lower
detail figure). The phase shift between I- and Q-signals should be 90 degrees.
3.2.2.1 RF operating voltage VBAT_ASIC ok?
• See section “RF operating voltage VBAT_ASIC ok?”
3.2.2.2 RFBUS signals ok?
• GSM receiver has to be active before RFBUS signals can be measured. Procedure is explained
in section “GSM RX chain activation for manual measurements”. Also WCDMA/GSM transmitter
and WCDMA receiver activation can be used for the measurement but then RFBUS -signals
don’t necessarily look like in figures mentioned below.
• Measurements can be performed with an oscilloscope and a probe. Check all five RF BUS
signals:
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RFBUSDAT : Connect the probe to J7504. Typical RFBUSDAT -signal is shown in figures in section
6.5.9.3 “RFBUSDAT (GSM RX)” .
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RFBUSCLK : Connect the probe to J7505. Typical RFBUSCLK -signal is shown in section 6.5.9.1
“RFBUSCLK (GSM RX)” and 6.5.9.2 “RFBUSCLK and RFBUSENA (GSM RX)”
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RFBUSENA : Connect the probe to J7506. Typical RFBUSENA -signal is shown in section 6.5.9.2
“RFBUSCLK and RFBUSENA (GSM RX)”
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RXRESETX : Connect the probe to J7515. RXRESETX -signal is a constant 2 V DC-signal after GSM
transceiver has been activated the first time after phone boot up. The level of this signal
should be about 0 V before transceiver activation.
• TXRESETX : Connect the probe to J7517. TXRESETX -signal is a constant 2 V DC-signal after GSM
or WCDMA transceiver has been activated the first time after phone boot up. The level of this
signal should be about 0 V before transceiver activation.
3.2.2.2.1 RAP3G (or Vinku or Hinku) faulty?
• RAP3G (D2800) cannot be replaced.
3.2.2.3 Hinku (N7500) regulator voltage VR1 ok?
• GSM receiver has to be active before Hinku’s VR1 voltage can be measured. Procedure is
explained in section “GSM RX chain activation for manual measurements”.
• Measurements can be done with an oscilloscope and a probe.
• Connect the probe to C7504 (or C7505)
• VR1 voltage level should be 2.65 – 2.86 V. Typical value is 2.7 V.