Motorola HT1250-LS+ - Emergency Alert and Radio Check Procedures

Maintenance 4-13
START
Is
RX LO
signal
present?
Tx Carrier?
VCO OK
Check
R3829
Is
TRB
(U3801
Pin 19) 3.2V in
TX Mode?
Pin 10
>1V?
L3831,
L3832,
L3833 O/
C?
Change
L3831, L3832
Change
U3801
AUX 3
High in TX
Mode?
Check U3701
Pin 2 for 3.2V
Is
U3801
Pin 19 0V
in RX
Mode?
AUX 3
Low?
Change
U3801
V ctrl 0V
or 13V?
L3821,
L3822,
L3823 Open
Circuit?
Change
U3801
Change
L3821,
L3822 &
L3823
Change
U3701
Troubleshoot Q3802 and
associated circuitry
A
A
No
No
Ye s
Ye s
Ye s
No
No
Ye s
No
Ye s
No
Ye s
No
No
Ye s
Ye s
Ye s
No
Check R3811,
L3811 for dry joint
or faulty
No
Troubleshooting Flow Chart for VCO
Ye s
RF
Signal at
U3801
Pin 8
No
Ye s