Motorola ASTRO Digital XTL 5000

6881096C74-B May 25, 2005
Troubleshooting Charts: Flowcharts 5-33
5.6.19 RX Back-End—Poor SINAD or No Audio (380–470 MHz and 450–520 MHz)—
Part 2 of 3
Figure 5-23. RX Back-End—Poor SINAD or No Audio (380–470 MHz and 450–520 MHz)—Part 2 of 3
No
3
3
1
R5013
= 5.0V?
No
Yes
Yes
R5013 = 0.0V?
No
Yes
Freq 2nd LO
VCO <107.4
MHz?
No
Yes
Measure
control voltage
at R5013
Inspect 2nd LO VCO
for missing parts or
solder defect
Yes
No
Visual
inspection
OK?
Repair defects
and/or replace
suspect parts
Replace
varactor diode
D6051
R5013
VOLTS DC
NOMINAL
FREQ (MHz)
0.0
1.6
4.0
5.0
68.0
71.1
75.6
77.0
Freq 2nd LO
VCO <107.4
MHz?