June 15, 2005
6815854H01-A
5-44
Troubleshooting Charts:
Flowcharts
5.6.33 Poor RX Sensitivity or No RX Audio (700–800 MHz)—Part 1 of 2
Figure 5-33. Poor RX Sensitivity or No RX Audio (700–800 MHz)—Part 1 of 2
MAEPF-27875-O
Poor Rx
Sensitivity or no
Rx audio
Measure Transceiver
Sinad by injection
signal at antenna port
Yes
Yes
3kHz FM Deviation
1kHz Audio tone
Sinad
< - 119.1dBm?
Check RF level at
Mixer LO injection port
(U6251 Pin 3 side 1)
Receiver
is working
properly
No
Yes
Good?
1
Check Q6350,
Q6251, Q6252,
Q6253, Q6254
and make any
necessary repairs
No
Yes
RF level
at ~ 14dBm?
Check RX front-end
filter switching
voltage Table
Check Receiver
VCO troubleshooting
flowchart
(LO injection section)
No
Yes
RX Switching Voltages
Receiving at
700MHz Band
Receiving at
800MHz Band
Test Points
TP6256, 58,
60, 62
TP6255, 57,
59, 61
TP6254
LNA U6250
0V
7.6V
2V
3V
4V
7.6V
5V at Pin 1
Содержание XTL 1500
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Страница 19: ...xviii List of Figures June 15 2005 6815854H01 A This page is intentionally left blank ...
Страница 25: ...June 15 2005 6815854H01 A xxiv CommercialWarranty Notes ...
Страница 35: ...June 15 2005 6815854H01 A xxxiv Model Numbering Charts and Specifications Notes ...
Страница 49: ...June 15 2005 6815854H01 A 2 12 Product Overview Controller Section Notes ...
Страница 161: ...June 15 2005 6815854H01 A 4 36 Troubleshooting Procedures Power Amplifier Procedures Notes ...
Страница 225: ...June 15 2005 6815854H01 A 5 64 Troubleshooting Charts Flowcharts Notes ...
Страница 429: ...8 2 Flex Cable Pin Out Lists Flex Cables June 15 2005 6815854H01 A Notes ...
Страница 441: ...June 15 2005 6815854H01 A Glossary 10 Notes ...
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