Troubleshooting
68P02963C70-O
3 - 11
DC Distribution (SWB+) Test
Use this test on a unit with the following symptoms: no SWB+.
Note: This test will be performed using TetraCom SW application commands <SWB
EN/Dis>.
Is the voltage OK?
Is the voltage
0.3V?
<
Are voltages OK?
Is the voltage OK?
TetraCom
command
“SWB Dis”
SWB+
current limit
test OK
TetraCom command
“SWB EN”
Check R119
Refer to the
DC distribution (V2-2.775 V)
Test flowchart
Check If U104 pin 5 is
shorted to ground.
Repair, as necessary.
Check U104 pin 3
Voltages >2.0V for “SWB EN”
<0.4V for “SWB Dis”
(SPICS4A-Redcap)
Check U104.
Replace if necessary
Check U104 pin 1
for 3.6 Vdc ()
Check U104 pin 6
for 3.6 Vdc
No
No
No
No
Yes
Yes
Yes
Yes
Summary of Contents for MTH500
Page 10: ...Contents x 68P02963C70 O THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 14: ...Foreword xiv 68P02963C70 O THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 18: ...Overview 1 4 68P02963C70 O THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 50: ...Theory of Operation 2 32 68P02963C70 O THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 76: ...Troubleshooting 3 26 68P02963C70 O Offset VCO Test ...
Page 78: ...Troubleshooting 3 28 68P02963C70 O This page left blank intentionally ...
Page 82: ...Programming the Radio 4 4 68P02963C70 O This page left blank intentionally ...
Page 100: ...Maintenance 5 18 68P02963C70 O Figure 23 Exploded View 1 2 3 4 5 7 6 X6 8 ...
Page 101: ...Maintenance 68P02963C70 O 5 19 Figure 24 Exploded View of Chassis Assembly 9 12 13 10 11 14 ...
Page 102: ...Maintenance 5 20 68P02963C70 O ...
Page 134: ...SCHEMATIC DIAGRAMS MTH500 Flex CD 6 32 68P02963C70 O This page left blank intentionally ...
Page 140: ...Replacement Parts and Kits 6 68P02963C70 O ...
Page 141: ...Replacement Parts and Kits 68P02963C70 O 7 ...
Page 142: ...Replacement Parts and Kits 8 68P02963C70 O ...
Page 144: ...Test Equipment Service Aids Tools A2 2 68P02963C70 O THIS PAGE INTENTIONALLY LEFT BLANK ...