Troubleshooting Flow Chart For Receiver Rf (Sheet 1 Of 2) - Motorola VHF2 Service Information

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Troubleshooting Flow Chart for Receiver RF (Sheet 1 of 2)

Go to
DC Section
Check Q306, Q300
and U403
Check Q304, D305
and U403
Go to SYN
Section
Go to
DC Section
Yes
Problem in 12 KHz and
25 KHz channel spacing
9V on
Yes
No
R310 (LNA)
OK?
Yes
No
RX_EN
ON ?
No
Yes
LOC_DIST
ON?
No
LO
Yes
POWER
OK ?
No 5V
Yes
(IF AMP)
OK ?
Go
to A
START
Check Go to
RX_EN DC Section
Check
LOC_DIST
Check
TPI
Check 5V
on R336
Check 3V
on R339
TROUBLESHOOTING CHARTS
3 V
No
to U301
Okay ?
Yes
Check D301-304
Replace IF Filters( FL304, FL301)
If problem in 25 KHz spacing