Numbers In Brackets Refer To Accompanying Troubleshooting Procedure Overleaf; Troubleshooting Chart 1-8B, Control Head Models Ii & Iii - Motorola MCS 2000 Service Instructions Manual

Troubleshooting Chart 1-8B, Control Head Models II & III

Numbers in brackets refer to accompanying troubleshooting procedure overleaf

START
Radio
No
Check on/off switch (1.1)
can turn on/off?
(1.1)
Yes
5VDC
No
on TP3?
Check 5V supply (1.2)
(1.2)
Yes
Radio
No
resets control
head?
(2.1)
Yes
Reset
No
Check Q0655, U0660,
circuit works?
(2.2)
Yes
Under-
No
voltage detector
Replace U0660 (2.3)
works?
(2.3)
Yes
Micro-
No
Check Y0650 and U0653
processor clock
runs?
(3)
Yes
Check the following:
BUS + (4.1)
Serial bus
No
BUS- (4.2)
communication
OK? (4) BUSY (4.3)
"FAIL 01/90" BUS+/BUS- Comparator (4.4)
Radio never starts
Yes
after power on
stops only with accessory
Check the following:
SW B+ voltage in normal mode (5.1)
Multiplexer in normal position (5.2)
SW B+ and
PTT input (5.3)
No
multiplexing of MIC
Monitor input (5.4)
connector OK?
AUX input (5.5)
SW B+ in SB9600 Mode (5.6)
SW B+ in SB9600 Mode (high load) (5.7)
Yes
Multiplexer in SB9600 Position (5.8)
9-18 Troubleshooting
Error in radio!
D0660 (2.2)
(3)
Communication
Yes
on MIC Conn?
(4.5)
Accessory is defect!
No
Volume
No
Check R0696 (6)
control OK?
(6)
Yes
Keypad
Check electrical connection to µP.
No
OK?
Clean PCB or replace keypad (7)
(7)
Yes
Keypad
No
backlight
OK?
Yes
Yes
Check Q0650, Q0651
and Q0652 (8.1)
LED
No Check U0654, Q0657,
indicators
Q0658, Q0659 and LEDs (9)
OK?
Yes
LCD
No
backlight
OK?
Yes
Yes
Check U0654, Q0666,
Q0667 and U0656 (10.1)
Check the following:
Text in
Defect outside segment area (11.1)
No
LCD display
Missing segments? (11.2)
OK?
Weak segments? (11.3)
LCD bias voltage (8 volts)? (12)
Yes
Check the following:
Check input from P0651 to µP U0653 (13.1)
Secure
No
keyloading
Check multiplexer position (13.2)
OK?
Check connections through multiplexer
including ESD protection diodes (13.3)
Yes
Replace U0660 (2.3)
Rotary
No
switch OK?
Check R0697 (14)
(14)
(model II
only)
Yes
Micro-
No
Replace and factory programming
processor
and alignment necessary
OK?
Yes
END
No
All LEDs?
Check the LEDs
(8.2)
No
All LEDs?
Check the LEDs
(10.2)
MAEPF-25122-O