Dc Distribution (Swb+) Test - Motorola MTH500 Service Manual

Yes
68P02963C70-O

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>.
TetraCom command
"SWB EN"
TetraCom
Is the voltage
command
< 0.3V?
"SWB Dis"
No
SWB+
current limit
test OK
Check U104 pin 6
for 3.6 Vdc
Yes
Is the voltage OK?
No
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)
No
Are voltages OK?
Yes
Check U104 pin 1
for 3.6 Vdc (Filt_B+)
No
Is the voltage OK?
Yes
Check U104.
Replace if necessary
Check R119
Refer to the
DC distribution (V2-2.775 V)
Test flowchart
Troubleshooting
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