Trc Board Dc Voltage Troubleshooting Chart; Trc Tx Audio Troubleshooting Chart - Motorola ASTRO Spectra Instruction Manual

TRC BOARD DC VOLTAGE
START
Set up for radio test,
be sure all connectors,
switches and jumpers
are in connect positions
Check AC source
Is
No
is present and
12.0V present
that power supply
at J11-1?
is functioning
Yes
Replace 9.6V
Is
No
regulator (U100)
9.6V present
and check for
on audio IC s?
short in circuit
Yes
Check for
Is
No
correct operation
4.8V present
of U102 and replace
at audio IC s?
if necessary
Yes
Is
Replace VR101
No
5V present
and check
at U131-3?
for short in circuit
Yes
Is
Replace 5V regulator
No
5V present
(U132) and check
at U132-2?
for short in circuit
Yes
STOP

TRC Board DC Voltage Troubleshooting Chart

58
START
START
START
START
START
MAEPF-26154-A
Check that U127,
U123, and U129 are
operating correctly.
2
No
Is
Check for
FILTER_CLOCK
Yes
proper operation
a 0-5V square wave and
of HY2 and replace
at 110.4kHz?
if necessary.
2
Check that
HY2 is inserted
properly.
Check that JU101
is installed and
U110 and U105 are
operating correctly.
3
Check for proper
operation of U106
and U107 and
replace if necessary.
4
Check
P101 and U106.
5

TRC TX Audio Troubleshooting Chart

TRC TX AUDIO
START
NOTE;
Set up
To set up radio for test, be sure all connectors,
radio for test.
jumpers, switches, are configured appropriately.
Refer to manual for proper set up procedure.
Inject a 440mVrms
Set S100
1kHz signal into
correctly and
the TX wireline.
reset consolette.
1
No
Is signal Is
No
S100-4
at TP1 0dBm
–1dB? off?
Yes
Yes
2
Is
Is 1kHz Check U117
No No
voltage on C506
signal present comparators for
approximately
at TP4?
correct operation.
0VDC?
Yes Yes
3
Is 1kHz
Remove drain
No
signal present
and source leads
at J1-23?
of Q113.
Yes
4
Is 1kHz Is
Trace signal
No No
signal present signal present
from input
at J1-13? at TP1 now?
to find failure.
Yes
Yes
5
Is 1kHz
No
Replace
signal present
at J3-46? Q113.
Yes
1
STOP
6881086C22-B
1
1
MAEPF-26157-O