Motorola CM Series Service Information page 17

Controlhead CM160/CM360 Troubleshooting Chart
2.2 Button/Tones Select Error (Page 1 of 2)
Button/Tones Check
Check Voltage Levels on
TP401 (Keypad Col)
and TP402 (Keypad Row)
(see table on next page)
Right
No
Voltage
Up Key?
YES
Right
No
Voltage
on Down
Key?
YES
Right
No
Voltage
on P1-P4
Keys ?
YES
Connect DTMF Mic
to TELCO Connector
Is there
0.75 Vdc on
MIC_SENSE
R429, on radio
A
Check R13, R45
on Control Head
Check R12, R49
on Control Head
Check R31, R29
R51, R11
on Control Head
Check Control Head
No
connectivity continuity
and R429, R430, D401
(Main Board)
3-5