Troubleshooting Charts:
RX RF Failure
5-31
RX RF Failure – Page 2
1
Remove shield,
SH2. Measure
2nd LO at
TP601.
Signal
Present?
2nd LO: 107.4 MHz
LO Freq. OK?
700-800: 107.4 MHz
VHF/UHF1/UHF2: 107.4 MHz
Measure
CLK_SSI_RX, output side of R618
DIG_DATA_SSI_RX_FS, output side of R616
DIG_DATA_SSI_RX_DOUTA, output side of R617
Observe 0 to 1.875Vdc
digital signals
Levels
OK?
Measure
CLK_SSI_RX at
output side of R618
CLK_SSI_RX
= 1.2 MHz?
DIG_DATA_SSI_RX_FS = 20 kHz
sync pulse
DIG_DATA_SSI_RX_FS
OK?
DIG_DATA_SSI_RX_DOUTA = 16-bit I,
16-bit Q.
DIG_DATA_SSI_RX_DOUTA
OK?
Go to Controller RX
AUDIO flowchart
Yes
Yes
11
10
No
No
9
No
Yes
10
No
Yes
Yes
10
No
Q601-3 =
5.0 Vdc?
Q601-2 =
3.8 Vdc?
Check Voltage
Regulator U200
Replace
Q601
Remove SH17.
Inspect 2nd LO
VCO
Replace
U602
Repair
Defects
Visual
examination
2nd LO DC bias
No
No
Yes
No
No
Yes
Check
Controller
No
Yes
Yes
Yes
Note:
RF Test frequency used:
VHF: 154.275MHz
UHF1: 424.975MHz
UHF2: 485.075MHz
700: 769.0625MHz
800: 860.0625MHz
Measured with a High Frequency Probe for relative comparisons and troubleshooting only.
Actual S21 gain or loss may differ if the test point is not 50 ohms.
Sampling Clock
Present? Signal
side of C620,
18 MHz
Summary of Contents for APX 2000
Page 1: ...APXTM TWO WAY RADIOS APX 1000 APX 2000 APX 4000 APX 4000Li DETAILED SERVICE MANUAL ...
Page 4: ......
Page 6: ...iv Document History Notes ...
Page 8: ...Notes vi Commercial Warranty ...
Page 10: ...Notes ...
Page 22: ...xiv List of Figures Notes ...
Page 226: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 688: ...Index 4 Index Notes ...
Page 690: ...ii Notes ...
Page 700: ...xvi List of Figures Notes ...
Page 806: ...5 50 Troubleshooting Charts PA Failure Notes ...
Page 1008: ...8 178 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 84012621001 Notes ...
Page 1062: ...8 234 Schematics Boards Overlays and Parts Lists Keypad Board M2 and M3 PC000261A01 Notes ...
Page 1064: ...ii Notes ...
Page 1068: ...Notes A 4 EMEA Warranty Service and Technical Support Further Assistance From Motorola ...
Page 1090: ...Glossary 10 Glossary Notes ...
Page 1094: ...Index 4 Index Notes ...
Page 1095: ......