Motorola HT1250-LS+ Service Manual page 52

4-16
B
Inject RF into J101
IF Signal
at L304?
No
RF Signal at
T301?
No
RF Signal at
C308?
No
RF Signal at
C303?
No or
weak RF
RF Signal at
C300?
No
Check harmonic filter L101 & L102 and
antenna switch CR101, CR102, L103,
and associated components
Trace IF signal
Yes
from L304 to
Q350. Check for
bad XTAL filter
1st LO O/P
Yes
No
OK? (+8 dBm
at T302 Pin 6?)
Locked?
Check T301, T302,
and CR301
Yes
Yes
Check filter FL301 and
associated circuitry
Yes
Check RF amp (Q301)
Stage
Yes
Check filter FL300 &
associated circuitry
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
Q350 collec-
Check FGU
Is 5V supply
Check U202
Yes
tor OK?
IF signal
present?
Before replac-
ing U350, check
U350 voltages;
No
trace IF signal
path
Check for
Yes
3.0VDC @
Q350-C
No
Yes
present?
No
Maintenance
A
A