5: Testing and Troubleshooting
5-4
TW7201I-MS
CAUTION: Use extreme caution when powering the TW7201I from
an AC power source. Using AC power produces high voltage on
the power supply board. Use a DC power source when performing
testing and servicing.
5.2.1
Transceiver
7000RI
1. Power on the TW7000 transceiver.
2. Verify the transceiver detects and indicates the presence of the 7000RI
option on the front panel LCD.
3. Verify the correct remote cable wiring (where applicable).
5.2.2
Power
If the TW7201I does not power up:
1. Verify the TW7201I is receiving the correct input power (13.8 Vdc or
110/220 VAC).
2. For AC input, verify the AC voltage selector card is set for the correct AC
input.
3. Check the fuses in the DC input/fuse block on the rear panel.
Note:
If the fuse is blown, determine the reason and perform the
necessary repairs before continuing with further testing.
4. Verify the DC input voltage on the Power Supply/Interface board at test
points TP1 and TP2 is 12 Vdc.
5. Check the
PWR OFF/VOL
switch. Ground the PWRON line to verify
proper switch operation. The relay on the Power Supply/Interface board
should activate.
6. Measure the following voltages on the Power Supply/Interface board: TP1
input voltage (source voltage), TP2 12 Vdc.
7. Check
PWR OFF/VOL
knob operation and backlight operation (
ALPHA 24
).
5.2.3
Receive Audio
If there is no receive audio or noise at the TW7201I:
1. Verify the receiver signal/noise is present at the transceiver. Check for
correct DHSL Modem board configuration according to the system
configuration.
Note:
The audio is transmitted as digital data. If data information (for
example, front panel) is okay but there is no receive audio, check JU5,
JU6, JU7 and JU8.
Summary of Contents for TW7201I
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Page 86: ...TW7201I MS Figure 5 4 DHSL Modem Board Schematic Diagram 994184 Rev E 5 25 ...
Page 99: ...TW7201I MS Figure 5 6 Power Supply Interface Schematic Diagram 994222 Rev D 5 39 ...
Page 104: ...TW7201I MS TW7201I MS Figure 5 8 Switching Board Schematic Diagram 994149 Rev A 5 45 ...
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