Motorola Mototrbo - 4.0 Troubleshooting Flow Chart for Rx VCO

1-10 Troubleshooting Flow Chart for Rx VCO
4.0 Troubleshooting Flow Chart for Rx VCO (Sheet 1 of 2)
No Receive Signal at C0401
Visual Check of Board Ok?
Correct Problem
Check 0 VDC at C0319?
Check 5.0 VDC at
R0313 & R0314?
Check components C0313,Q0301
Q0302,R0313 & R0314 for short or
open and replace Q0301 and Q0302
if needed
Check Controller troubleshooting
flow chart
Radio did not boot up properly or
check 9V3 regulator
Check
L0301,R0306,R0308,R0303,R0304,L
0307,R0307,C0306 & Q0300 and
replace Q0300 if needed
Check components between C0307
and R0312 for short and open
Check components between R0301
and C0307 for short and open
Check RFICthesizer troubleshooting
flow chart
Check 1.8 VDC at R0219
Radio not programmed for Receive
mode or Q0202 not functional
Is RF prescaler level at TP0001
between 120-300mV
Is 8.0 VDC at L0301?
Vbe ~ 0.8 VDC for Q0300?
RF Signal present at C0307?
RF Signal present at R0301?
Is 8.2 VDC at L0207
Is 8.2 VDC at R0208
No
No
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
A
No
No
A
No
No