Volume Set Error Troubleshooting Chart - Motorola XTS 2500 Service Manual

6.1-10

6.1.11 Volume Set Error Troubleshooting Chart

Refer to "No
Receive Audio"
flow chart
February 14, 2012
VHF Troubleshooting Charts: Volume Set Error Troubleshooting Chart
Volume
Set Error
Verify operation
of volume knob
per "Button Test"
flow chart
Yes
Volume
check OK?
No
Using a voltmeter,
measure voltage at
R505 when volume
knob is on. The value
should be 3.0V.
Replace
Volume
Switch
Synopsis
This chart relates to a failure in the volume
set knob. Basic failure modes are as follows:
1) Bad connection
2) Defective volume control pot
3) Defective MAKO IC (U701)
4) Problem in receive audio circuit
Voltage
Functional?
No
Measure voltage from
C520 to GND while
moving volume knob
from min to max. Max
volume is 2.50V
Volume
No
pot OK?
Yes
Verify contact
with circuit
board
Yes
Replace
U701
MAEPF-27336-O
6816985H01-F