Motorola ASTRO Digital XTL 5000

6881096C74-B May 25, 2005
Troubleshooting Charts: Flowcharts 5-51
5.6.37 RX Back-End—Poor SINAD or No Audio (700–800 MHz)—Part 2 of 3
Figure 5-39. RX Back-End—Poor SINAD or No Audio (700–800 MHz)—Part 2 of 3
No
3
3
1
TP6001
= 5.0V?
No
Yes
Yes
TP6001
= 0.0V?
No
Yes
Freq
VCO <71.1
MHz?
No
Yes
Freq
VCO >75.6
MHz?
Measure
control voltage
at TP6001
Inspect 2nd LO VCO
for missing parts or
solder defect
Yes
No
Visual
inspection
OK?
Repair defects
and/or replace
suspect parts
Replace
varacter diode
D6051
MAEPF-27807-O
TP6001
VOLTS DC
NOMINAL
FREQ (MHz)
0.0
1.6
4.0
5.0
68.0
71.1
75.6
77.0