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 17) is routed directly from the radio battery and is used 
for LCD and keypad backlight LEDs and indicator LEDs.
Power supply B+ (pin 18) is routed from the radio battery via the radio on/off 
switch and provides Vcc via regulator U0654.
Option SW B+ (pin 1) is the power supply output to the connected accessory. 
The current is monitored by the Control Head to operate the multiplexer. 
(Refer to Mode Select) 
Audio 
conÞguration 
The Control Head can be conÞgured for Handset audio or Speaker+ which is a 
balanced output from the radio. Handset audio is conÞgured by inserting 
R0676 in the line from pin 8 to the microphone connector. Speaker + audio is 
conÞgured by inserting R0675 in the line from pin 1 to the microphone 
connector. Note that only one resistor R0676 or R0675 must be Þtted. 
Volume Control /
on-off 
Front panel switch/potentiometer R0698 controls the volume via A/D 
converter PD0 (pin 14) in micro-controller (  
m  
C) U0653. The centre of the 
potentiometer is a push button switch used for microphone input and power 
on-off. When activated the microphone line (pin 9) is connected to ground. 
Micro-controller  
Micro-controller U0653 controls 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). 
The   
m  
C is reset from the radio via the reset line (pin 3) and Q0652.The   
m  
C is 
also reset by under voltage detector U0657 when Vcc drops below 4.6V. 
Xtal Oscillator 
The xtal oscillator is built using on chip oscillator gates of the microprocessor. 
The xtal is a standard 4 MHz ceramic resonator. 
LCD 
Backlight 
The backlight consists of 10 LEDs. Light intensity is in 3 levels including off 
and is software controlled by bus commands via   
m  
C U0653. 
						

							 
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 created by the voltage divider R0701, R0702 and 
R0703. This gives four voltages: supply voltage (VDD), V1, V2 and V3=GND. 
The COM and SEG outputs from U651 jump between these 4 bias voltage 
levels, which create the on and off AC voltage for each LCD segment.
Resistors R0715 and R0716 prevent U0651 from going into test mode during 
power up.
The LCD supply voltage is controlled by the microcontroller U0653 PA6. 
Display 
Display (H0650) is a transmissive/reßective positive LCD display. The Control 
Head has one line of 8 characters with Þxed symbols on top, four key-related 
symbols on the bottom and three colour indicators. 
Color Indicators 
The three color indicators are 4 LEDs D0679, D0680, D0681 and D0682. There 
are two yellow LEDs in order to increase the colour intensity. 
Keypad 
Backlight 
The keypad backlight is turned on and controlled along with the LCD 
backlight. 
Keypad 
The keypad is a static input with 10 kohms pull-up resistors. There is no 
scanning, but simply one input for each key. Debouncing control is handled 
by the software. 
Mode Select 
To reduce the number of pins on the microphone connector multiplexing is 
utilised to switch between the 3 different modes, Normal mode, SB9600 mode 
and Keyload mode. 
Multiplexer 
Operation 
The multiplexer comprises U0655 and U0656. Inputs to the multiplexer are 
from the microphone connector pins 3, 6 and 7. The multiplexer is switched 
either by a current sensing device (Q0662, Q0663), for Normal and SB9600 Bus 
modes, or by software for keyload mode. Pin 1 of the microphone connector 
carries the output current of the connected device.
When the output current is below 30  
m  
A, the multiplexer is switched to the 
Normal mode.
When the connected device is an SB9600 device, the current is greater than 2 
mA and the multiplexer is switched to SB9600 mode. Note that when an 
SB9600 device is self-powered, i.e. no current consumption from the 
microphone connector, a dummy load must be connected to pin 1 to ensure 
a minimum current of 2 mA and force the multiplexer into the SB9600 mode. 
A Þeld programmer is an example of such a device.
In the Secure keyload mode, an A/D input on the  
m  
C U0653 (PD6) monitors 
the Speaker-output dc voltage.  
						

							 
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 Mode 
Typically a control microphone, intelligent handset or Þeld programmer is 
connected to the microphone connector. Inputs include Bus+, Bus- and Busy.
On selection of this mode Bus+ and Bus- are routed from the multiplexer via 
the bus comparator circuit (Q0655, Q0656 and U0658) to the   
m  
C bus interface 
(RD1/TD0). Busy is routed to the radio via the Busy line (pin 14). 
Secure Mode 
This is the secure keyload mode. The inputs in this mode include WE (Write 
Enable), KID (Key Insert Data) and Key Fail. On selection of this mode these 
inputs are routed from the multiplexer to the radio via pin 10 (WE), pin 12 
(KID) and pin 11(Key Fail). 
Models II 
and III 
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. 
Control Head model II contains a rotary switch in place of a full keypad.
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 17) is routed directly from the radio battery and is used 
for LCD and keypad backlight LEDs and indicator LEDs.
Power supply B+ (pin 18) is routed from the radio battery via the radio on/off 
switch. It is routed to the microphone connector current sensor device 
(Q0664) and provides Vcc via regulator U0650.
Option SW B+ (pin 1) is the power supply output to the connected accessory. 
The current is monitored by the Control Head to operate the multiplexer. 
(Refer to Mode Select) 
Audio 
ConÞguration 
The Control Head can be conÞgured for Handset audio or Speaker+ which is a 
balanced output from the radio. Handset audio is conÞgured by inserting 
R0665 in the line from pin 8 to the microphone connector. Speaker + audio is 
conÞgured by inserting R0664 in the line from pin 1 to the microphone 
connector. Note that only one resistor R0655 or R0644 must be Þtted. 
Volume Control/
Cn-Off 
Front panel switch/potentiometer R0696 controls the volume via A/D 
converter PD0 (pin 14) in micro-controller ( 
m  
C) U0653. The centre of the 
potentiometer is a push button switch used for microphone input and power 
on-off. When activated the microphone line (pin 9) is connected to ground. 
						

							 
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 the reset line (pin 3) and Q0655. 
Xtal Oscillator 
The xtal oscillator is built using on chip oscillator gates of the microprocessor. 
The xtal is a standard 4 MHz ceramic resonator. 
LCD 
Backlight 
The backlight consists of 36 LEDs in model I and 48 LEDs in model J. Light 
intensity is in 4 levels including off and is software controlled by bus 
commands via Expander U0654 (Q6, Q7). A temperature condition in the 
Control Head overrides the software commands such that on rising to 78 
°  
C or 
above the lowest light level or off is selected. 
Controller 
LCD controller U0651 contains the default character set. On Control Head 
model J the controller is expanded by the use of an LCD driver U0652. The 
LCD controller is connected to the  
m  
C via data bus PA0-PA7, while the control 
and read/write (R/W) lines are connected via PB5 and PB7 respectively. 
Power Supplies 
The LCD bias voltage drives the display segments. The bias voltage is divided 
into 5 levels by R0707 to R0711 and routed to the LCD controller (and LCD 
driver in Control Head model J) under  
m  
C control via U0655. The   
m  
C measures 
the bias voltage with respect to Vcc (TP3) at A/D port PD3. Another function 
of the bias voltage is temperature which is measured across R0742 at A/D port 
PD7. The  
m 
C calculates the correction to the bias voltage and adjusts the duty 
cycle of the PLMA output to U0655 accordingly. 
Display 
Display (H0650) is a double layer super twist LCD display. Control Head model 
I has one line of 14 characters with Þxed symbols on top, six key-related 
symbols on the bottom and RSSI symbol on the right-hand side. Control Head 
model J is similar but has two lines of 14 characters. The presence of a rotary 
switch tells the software that the display is a one-line display. 
Temperature 
Sensor 
m 
C U0653 measures voltage on PD7 which is controlled by dividers R0741 and 
R0742. R0742 is an NTC resistor which is placed in close proximity to the LCD 
display. The temperature sensor protects the backlight LEDs from failure and 
is also used to compensate the LCD bias voltage dependent on the LCD glass 
temperature. The protection temperature is 77 
°  
C   
±  
6  
°  
C. 
Keypad 
Backlight 
The backlight consists of 7 LEDs in model I and 13 LEDs in model J. The 
backlight can be switched on/off by the radio software, controlled via  
m  
C 
U0653 TCMP1 and TCMP2. A high pulse on TCMP1 turns on the backlight 
and a low pulse on TCMP2 turns it off. If the temperature rises above 78 
°  
C in 
the Control Head the  
m 
C turns off the backlight utilising the Temperature 
Sensor input. 
Keypad 
The keypad is a passive input scanning matrix such that each key has 3 poles. 
When a key is pressed a row and column are connected to ground and sensed  
						

							 
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 
numbers. 
Mode Select 
To reduce the number of pins on the microphone connector multiplexing is 
utilised to switch between the 3 different modes, Normal mode, SB9600 mode 
and Keyload mode. 
Multiplexer 
Operation 
The multiplexer comprises U0657, U0658 and U0659. Inputs to the 
multiplexer are from the microphone connector pins 3, 6 and 7. The 
multiplexer is switched 
either by a current sensing device (Q0664, Q0665), for Normal and SB9600 Bus 
modes, or by software for keyload mode. Pin 1 of the microphone connector 
carries the output current of the connected device.
When the output current is below 30  
m 
A, the multiplexer is switched to the 
Normal mode.
When the connected device is an SB9600 device, the current is greater than 2 
mA and the multiplexer is switched to SB9600 mode. Note that when an 
SB9600 device is self-powered, i.e. no current consumption from the 
microphone connector, a dummy load must be connected to pin 1 to ensure 
a minimum current of 2 mA and force the multiplexer into the SB9600 mode. 
A Þeld programmer is an example of such a device.
In the Secure keyload mode, an A/D input on the  
m 
C U0653 (PD6) monitors 
the Speaker-output dc voltage. If the output is short circuit to ground for more 
than 1 second, the  
m 
C senses this via R0689/R0690 network and switches the 
multiplexer to keyload mode via U0654 (Q1). This action overrides the current 
sensor device. 
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 via the multiplexer to the  
m 
C A/D port where the analogue voltage is measured and decoded for all four 
possible combinations of PTT/Monitor and the 4 Auxiliary levels. 
SB9600 Bus Mode 
Typically a control microphone, intelligent handset or Þeld programmer is 
connected to the microphone connector. Inputs include Bus+, Bus- and Busy.
On selection of this mode Bus+ and Bus- are routed from the multiplexer via 
the bus comparator circuit (Q0660, Q0661 and U0656) to the  
m 
C bus interface 
(RD1/TD0). Busy is routed to the radio via the Busy line (pin 14). 
Secure Mode 
This is the secure keyload mode. The inputs in this mode include DVP WE 
(DVP Write Enable), KID (Key Insert Data) and Key/Fail. On selection of this 
mode these inputs are routed from the multiplexer to the radio via pin 10 
(DVP WE), pin 12 (KID) and pin 11 (Key/Fail). 
						

							 
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 for the radio.
The following chart will give you an overview of the complete set of 
troubleshooting charts available for serviceing a radio.  
Figure 9-1   Troubleshooting Charts Overview
CHART 1-5
RX AUDIO
RX AUDIO
ROUTING
SIMPLIFIED
SCHEMATIC
CHART 1-3
ON/OFF
CIRCUITRADIO VOLTAGE
SIMPLIFIED
SCHEMATIC
CHART 1-9
CLOCK
DISTRIBUTION
CHART 1-13
POWER
CONTROL
CHART 1-10
SB9600
BUS RXCHART 1-11
SB9600
BUS TX
SB9600
VOLTAGE
TABLESB9600
BUSY
SIMPLIFIED
SCHEMATIC
SB9600
SIMPLIFIED
SCHEMATICTX AUDIO
ROUTING
SIMPLIFIED
SCHEMATIC
CHART 1-8A
MODEL ICHART 1-8B
MODELS II 
AND III CHART 1-6
SIGNALLINGCHART 1-4
TX AUDIOCHART 1-7
DC
DISTRIBUTION CHART 1-8
CONTROL
HEADS CHART 1-1
OVERALL RADIO
CHART 1-2
FAILURE CODES
3 SHEETS RF BAND
SPECIFIC
CHARTS
(VOL 2)
CHART 1-12
GPIO
CHART 1-9
CLOCK
DISTRIBUTION
Refer to the IC Troubleshooting
Procedure before replacing any ICs. 
						

							 
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
tuning with RSS.
GOTO Power Control
Chart 1-13.Radio Setup
A+ = 13.6V, Accessory Connector
plugged in, Control Head plugged in,
Emergency Jumper in place
(Speaker Jumper in place Model 1 only)
Put the radio
in CSQ test mode
(Note 1 and 2)
GOTO
Failure Code
Chart 1-2Pressing
On/Off Button, errors
on display?
 Display
OK?No
No
Errors
Yes
Yes
Yes
No
No
Yes No
No
No
No
Yes Yes
Yes
NoYesNo No
Display Yes
Errors
IF remote
cable, do all lines
have continuity and all
lines free of shorts
to other lines
TX power
OK?
TX deviation
OK?
TX output
centered on
frequency?
Press
monitor button
on control head. Audio
from speaker?
Sensitivity
OK? 
Audio distortion

						

							 
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
01/81
No
No
DATA on
U0105-13
No
YesDATA on
U0103-63
YesYes
U0104
OK?
No
Yes
Yes
U0108
OK?
No
Check
U0103
Repair or
Replace U0104Repair or
Replace U0108
Check
U0105
GOTO SB9600
Bus Rx Chart 1-10 
No
Fail
01/92
Problem
Fixed 
Check
U0103
Fail
01/81
No
Yes
Program firmware
Note 1Yes
U0103
OK?YesYes U0106
OK?
U0104
OK?
No
YesRepair or
Replace U0104
No
Repair or
Replace U0106
No
Repair or
Replace U0106
Check
CR0105
Note 1
This level of troubleshooting must be
performed by an authorized DEPOT center.
CHART 1-2   FAILURE CODES  (1 of 3)
1
To Sheet 2
WARNING
Refer to the IC Troubleshooting
Procedure before replacing any ICs.
 
Troubleshooting 
9 
						

							 
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 U0104
Check
U0105Check
U0103
GOTO SB9600
Bus Rx Chart 1-10
Yes
U0108
OK?
No
Repair or
Replace U0108
Yes
Yes No
No
DATA on 
U0105-13
Fail
01/84
No
Yes
Program
codeplugYes
DATA on
U0103-63
Yes
Yes
U0104
OK?
Yes
U0108
OK?
No
Check
U0105
Repair or
Replace U0104
Yes
No No
No
Repair or
Replace U0108
Fail
01/84
No
Problem
Fixed
Problem
Fixed
Error
01/02
Yes Fail
01/94
No
Problem
Fixed
Check
U0103
DATA on
U0105-13
No
GOTO SB9600
Bus Rx Chart 1-10
Fail
01/94
No
Yes
Program
codeplug
DATA on
U0103-63
No
DATA on
U0105-13No
Yes
Yes
Check
U0105Check
U0103
GOTO SB9600
Bus Rx Chart 1-10
2
To Sheet 3
1
From Sheet 1
WARNING
Refer to the IC Troubleshooting
Procedure before replacing any ICs.