5-28
Troubleshooting Charts:
RX RF Failure
RX RF Failure – Page 2
1
Remove
shield, SH11.
Measure 2nd
LO at TP601
Signal
Present?
2nd LO: 107.4 MHz
LO Freq. OK?
700-800: 107.4MHz
UHF1/UHF2: 107.4MHz
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_F
S OK?
DIG_DATA_SSI_RX_DOUTA = 16-
bit I, 16-bit Q.
DIG_DATA_SSI_RX_DOUT
A OK?
Go to Controller RX
AUDIO flowchart
Yes
11
10
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 SH4.
Inspect 2nd LO
VCO
Replace
U602
Repair
Defects
Visual
examination
2nd LO DC bias
No
No
Yes
No
No
Yes
Sampling Clock
present? Signal side
of C620, 18MHz.
Check
Controller
No
Yes
Yes
Yes
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 1.875
Vdc digital signals
Levels
OK?
Yes
No
Note: RF Test frequency used:
UHF1: 424.975MHz
UHF2: 485.075MHz
VHF: 154.275MHz
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.
Summary of Contents for Astro APX 3000
Page 1: ...APXTM TWO WAY RADIOS APX 3000 DETAILED SERVICE MANUAL ...
Page 2: ......
Page 4: ...Notes ...
Page 6: ...vi Document History Notes ...
Page 10: ...x Table of Contents Notes ...
Page 12: ...xii List of Tables Notes ...
Page 18: ...xviii List of Figures Notes ...
Page 22: ...xxii CommercialWarranty Notes ...
Page 46: ...3 20 Theory of Operation Main Board Notes ...
Page 84: ...3 58 Theory of Operation Bluetooth Notes ...
Page 208: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Page 222: ...7 14 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 282: ...8 60 Schematics Boards Overlays and Parts Lists Main Board Block UHF1 84012513001_A Notes ...
Page 390: ...8 168 Schematics Boards Overlays and Parts Lists Main Board Block VHF 84012512001_A Notes ...
Page 456: ...9 8 Debugging Fixture Powering up Covert Board Notes ...
Page 468: ...Glossary 10 Glossary Notes ...
Page 472: ...Index 4 Index Notes ...
Page 473: ......