Motorola Professional GP640 Service Information - Page 25

Browse online or download pdf Service Information for Radio Motorola Professional GP640. Motorola Professional GP640 28 pages. Professional radio, power distribution and controller
Also for Motorola Professional GP640: User Manual (32 pages), Specification Sheet (2 pages), Service Information (32 pages), Service Information (30 pages), Service Information (26 pages), Service Information (43 pages), Service Information (30 pages)

Print Page
Motorola Professional GP640 Service Information

Troubleshooting Flow Chart for VCO

5.0
Troubleshooting Flow Chart for VCO
Check R245
No
for dry joint
or faulty
A
U241
Pin 19 =0V
No
AUX 4
High?
No
Change
U201
U241
Pin 10
>1V?
Yes
Yes
L253
Open
Circuit?
No
Change
U241
Yes
Yes
Change
Q261
TRB =
Yes
5V? @U241
Pin 19
Change
L253
AUX 3
High?
Check U201
Pin 2 for 3.2V
VCTRL
Yes
0V or
13V?
No
Check for faulty
parts or dry joints of
L271, L273, C370,
C386, R339 & L320
START
Yes
No LO?
A
No
No
Carrier?
No
VCO OK
Yes
Check
R260
No
L243
Yes
Open
Circuit?
No
Change
U241
3-5
Tx
Yes
Change
L243