Troubleshooting Flow Chart For Vco - Motorola Professional Radio Service Manual

3-26
No TX LO or No
signal at U205 Pin
32 in TX
Check signal at
collector of Q201
Level >
+2 dBm
No
Check signal at
drain of Q203
Level >
-3 dBm?
No
Check C215, C216,
L207, L208, L209,
U203
Problem
fixed?
Yes
Done

Troubleshooting Flow Chart for VCO

Check L204, L211, L212,
L215, C221, C228, C229,
Yes
C230,C231, C235,C297,
R204, R234, R238
Yes
Replace Q201
No
Replace Q203
Low Band Troubleshooting Charts
No RX LO or No
signal at U205 Pin
32 in RX
Check signal at
collector of Q201
Yes
Yes
No
Replace Q202
and Q204
Check C200, C202, C203,
C222, C223, L201, L203,
TR201, CR202
Level >
+10 dBm?
No
Check signal at
drain of Q202
and Q204
Level >
+7 dBm?
No
Check DC volt-
age across R203
Level >
500 mV ?
Yes