Tektronix CSA 803A Stereo System User Manual


 
CSA 803A Service Manual
6Ć101
Other Troubleshooting
This section provides additional information and procedures for troubleĆ
shooting a faulty CSA 803A to the FRU level.
This procedure requires an Extended Diagnostics power supplies troubleĆ
shooting fixture. Refer to Table 4Ć2 for a complete description of the equipĆ
ment required.
Module Troubleshooting
If any Power Supply module problems are present, they appear when the
ON/STANDBY switch is set to ON. If the green light beside the ON label fails
to light, then check for the following conditions:
H The PRINCIPAL POWER SWITCH located on the back panel is in the ON
position.
H The line cord is connected to a functional power source with the same
output voltage set as the LINE VOLTAGE SELECTOR on the back panel.
H The fuse is good. If the fuse is blown, then replace the fuse.
H The fan is exhausting air from the instrument when the ON/STANDBY
switch is ON. A defective fan causes an overĆtemperature shutdown in
the power supply.
If these checks fail to correct the problem, connect the Extended DiagnosĆ
tics 11000ĆSeries Power Supplies Test Fixture to the Power Supply module
(refer to the documentation accompanying the test fixture for troubleshootĆ
ing techniques). The test fixture indicates which power supply voltage
source is at fault. To help isolate the source of the problem, set the instruĆ
ments ON/STANDBY switch to STANDBY, and disconnect the suspected
faulty power supply voltage source from the Power Supply module. Set the
ON/STANDBY switch to ON. If the test fixture does not record a fault, then
you have verified the suspected faulty power source. This procedure is only
effective for externally shorted power supplies. Once again, refer to the
documentation accompanying the test fixture for more troubleshooting
information.
This board is implicitly verified; that is, if all the other FRUs pass diagnostic
testing, then you can assume that the A4 Regulator board is operating correctly
as well.
Power Supply
Module
A4 Regulator Board