4-10
Maintenance
IF Signal at
C3281?
No
RF Signal at
T3301?
RF Signal at
C3353?
No
RF Signal at
C3346?
No
RF Signal at
C3341?
No or
Check harmonic filter L3531 & L3532,
C3532 and ant. switches D3521,
D3551, L3551 & associated compo-
nents.
Check filter between
C3341 & Q3302
Inject RF into J3501
No
Yes
Check RF amp (Q3302)
Stage.
Check filter between
Q3302 & T3301
Yes
Check T3301, T3302,
CR3301
Yes
1st LO
O/P OK? (+5
dBm at T3302
Pin 6?)
Locked?
Yes
Check FGU
Yes
Trace IF signal
from C3200 to
Q3200. Check for
bad XTAL filter.
No
Yes
Q3200 collec-
tor OK?
IF signal
present?
Before replac-
ing U3101,
check U3101
voltages; trace
IF signal path
Yes
Check
for 2.9 VDC
@ Q3200-C
Is 5V supply
present?
Check U3711
No
No
No
Yes
Yes
A
A
B
weak RF
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
Summary of Contents for HT1250-LS+
Page 10: ...viii ...
Page 12: ...x Product Safety and RF Exposure Compliance ...
Page 16: ...1 4 Introduction ...
Page 58: ...4 22 Maintenance ...
Page 64: ...5 6 Schematic Diagrams Overlays and Parts Lists ...