Motorola Radio Mcs2000 Vol 1 68p81083c20 A Manual

 
Control Heads 8-1 
Control Heads 
8 
Model I 
Introduction 
The Control Head forms the interface between the radio and the user. It 
contains an LCD display, on/off and volume switch, keypad and control keys.
The microprocessor controlled Control Head interfaces to the radio control 
logic board J0650 via an 18-pin connector on the back of the unit. An external 
microphone/speaker is connected to the Control Head via the front mounted 
microphone connector P0651. 
Power supplies 
Power supply A+ (pin...

 
8-2Control Heads 
Driver 
The LCD driver U0651 contains the default character set. Its interface is a four 
line serial interface. The LCD driver is connected to the   
m  
C on pins PA0 - PA3. 
The driver has a built in oscillator with one external resistor, R0700, deÞning 
the clock frequency. The oscillator runs at approx. 25 kHz giving an LCD frame 
frequency of approx. 48 Hz. 
Power Supplies 
The LCD driver and bias voltages are powered either from 5.0 V or 5.7 V. The 
LCD bias voltage levels are...

 
Control Heads8-3  
If the output is short circuit to ground for more than 1 second, the   
m  
C senses 
this and switches to keyload mode (via PC7 output). 
Normal Mode 
Typically a microphone with no microprocessor is connected to the 
microphone connector. Inputs in this mode include PTT, Monitor and 
Auxiliary. In Normal mode these inputs are routed to the   
m  
C A/D port where 
the analogue voltage is measured and decoded for all possible combinations of 
PTT, Monitor and Auxiliary. 
SB9600 Bus...

 
8-4Control Heads 
Micro-controller  
Micro-controller U0653 and Data Expander U0654 control the operation of 
the Control Head. The  
m 
C exchanges data with the radio via the SB9600 bus 
(TD0 and RD1) and monitors inputs from the microphone connector via the 
A/D port (PD0-PD7). In addition keypad and LCD data is processed via ports 
A, B and C. Both the  
m 
C and the Expander are reset by under voltage detector 
U0660 when Vcc drops below 4.6 V. Both devices can also be reset from the 
radio via...

 
Control Heads8-5  
by the  
m 
C (PB0-PB4/PC0-PC4). Only Control Head model J contains a full 
keypad. 
Rotary Switch 
Rotary switch R0697 (Control Head model I only) is a double wiper 
continuous turn 16-step potentiometer. The two wipers are connected to two 
A/D inputs on the  
m 
C U0653 (PD1, PD2). One input covers 8 steps from 0 
°  
 to 
180 
° 
 and the other the 8 steps from 180 
° 
 to 360 
° 
. The switch function is 
software programmable and may be used for example to select shortform call...

 
8-6Control Heads 
NOTES 

 
Troubleshooting 9-1 
Troubleshooting 
9 
This chapter contains the troubleshooting ßowchart diagrams for the Overall 
radio and for the Controller section of the radio as well as the Control Heads. 
Troubleshooting ßowcharts for the RF section will be found in Volume 2a, 2b, 
2c, 2d or 2e of this manual depending on the frequency range.
Refer to the SECURENET option service manual (part number 68P81083C25) 
for troubleshooting information and troubleshooting ßowchart diagrams for 
the SECURENET Option...

 
9-2Troubleshooting 
Troubleshooting Chart 1-1, Overall Radio  
CHART 1-1   OVERALL RADIO
GOTO
Signalling
Chart 1-6
GOTO
Band Specific
RX IF
GOTO
Band Specific
RX Front End
GOTO
RX Audio
Chart 1-5
Connect signal generator
to antenna connector.
Set to channel frequency.
Check frequency
tuning using RSS.
GOTO Band Specific
Synthesizer Chart
GOTO
TX Audio
Chart 1-4
GOTO
DC Distribution
Chart 1-7
  GOTO  
Control Head
Chart 1-8
Attach known good
control head using
control head
extender cable
Check TX power...

 
Troubleshooting 9-3 
Troubleshooting Chart 1-2 (1 of 3), Failure Codes 
Fail
01/92
Fail
001Check
U0105
Check
U0103
GOTO SB9600
Bus RX Chart 1-10GOTO Band Specific
Synthesizer Chart
No
Note 1
NoNo
NoNo
Yes
Radio
power upProgram
codeplug using
depot toolDATA on
U0103-63
DATA on
U0105-13
Yes Yes
YesCheck
U0101
Repair or
Replace R0101Repair or
Replace U0103
Fail
01/88Yes
5V
R0101
No No
Problem
Fixed
Fail
01/82
No
YesYes U0103
OK?
No
Fail
01/98
No
Yes
Fail
01/82
No
Yes
Program
codeplug
Problem
Fixed
Fail...

 
9-4Troubleshooting 
Troubleshooting Chart 1-2 (2 of 3), Failure Codes 
Fail
01/90
No
Yes
No Voltages
on J0403-5, 6,18
per Chart
14
U0104
OK?
YesYes U0103
OK?
DATA on
U0105-13
Yes
NoCheck
U0105
No
Repair or
Replace U0104
No
Repair or
Replace U0103
Yes Clock
signal on
U0103-34
NoYes
GOTO
Clock Distribution
Chart 1-9
No J0405
OK?
Yes
GOTO
Control Head
Chart 1-8
Repair or
Replace J0405
GOTO SB9600
Bus Rx Chart 1-10
Error
01/02
No
Yes
Yes Program
codeplug
DATA on
U0103-63Yes
U0104
OK?
No
Repair or
Replace...