Motorola Radius CM300 User Manual

3-4 TROUBLESHOOTING CHARTS
2.0 Control Head CM300/PM400 Troubleshooting Chart
2.1 Control Head Failure
Back light
OK ?
Check 9.3V on
Q12, U1 and associated
parts and U8
No
Control Head Check
Power-up
Alert Tone
OK ?
Check Speaker
Connection
No
Indicator
LED’
S
OK ?
Check
Q8–Q10, U8 and 9.3V
No
Display
OK?
Check LCD
connections, U3 for 5V,
Osc. pins 1 & 2 activity
SCI thru via U4
No
Up/Down
P1 and P2
Alert Tone
Buttons
OK?
Check keypad resistors
No
EXT
PTT
OK ?
Check Q13, Q802
No
Communication Ok
Check Q803, Q14 and
associated parts
Control Head is OK
YES
YES
YES
YES
YES
YES
No

Motorola Radius CM300 Specifications

General

Brand	Motorola
Model	Radius CM300
Category	Radio
Language	English