User's Manual

6881094C31-C October 14, 2003
Troubleshooting Charts: Top/Side Button Test 5-17
5.10 Top/Side Button Test
MAEPF-27400-O
Use RSS
to enable
button
Replace
U504
Replace Front
Cover Housing
Assembly
Verify connections
and control top/PTT
flex circuit and
repair as necessary
Using RSS,
verify problem
button is enabled
for function
Levels
correct?
Verify physical
operation of
buttons
Buttons
OK?
Button
check OK?
Buttons
Enabled?
Using a voltmeter, measure the voltage at
U504 pin 3 while depressing the following
buttons: Emergency, Side Button 1, Side
Button 2, and Side Button 3.
The probe points are as follows:
Button
Emergency
Top Side
Middle Side
Bottom Side
None Pressed
Voltage
0.18V
1.40V
1.70V
2.00V
2.50V
Top/Side
Button Test
Synopsis
This chart relates to a failure in
reading the buttons: Emergency,
Side Button 1, Side Button 2, or
Side Button 3.
Basic failure modes are as follows:
1) Failure in controls flex circuit
2) Bad connection
3) Defective Switch
4) Defective A/D port in GCAP II
Verify operation
of zone knob
using Button Test
flowchart
No
No
Ye s
Ye s
No
Replace
U501
Problem
fixed?
End
No
Ye s
No
Ye s
Ye s