Tait TB8100, Service Manual

Page: 138 / 306

138 Power Amplifier Fault Finding TB8100 Service Manual
© Tait Electronics Limited September 2006
8.6 Initial Checks
You can use the TB8100 Service Kit and Calibration Kit to check the basic
operation of the PA without removing the cover.
■
To check whether the PA powers up correctly and generates any alarms,
carry out
Task 1 , Task 2 , and Task 3 .
■
If the PA has low RF output power, go to Task 4 .
■
To check the operation of the ambient air temperature sensor board, go
to
Task 5 .
Task 1 —
Check Power-up
and LEDs
1. Before starting any of these fault finding procedures, you must iden-
tify the model and hardware configuration of the PA under test.
“Identifying the PA” on page 129 explains how to identify a PA from
the product code printed on a label on the rear panel.
2. Set up the test equipment as shown in Figure 8.3 on page 134 (28V
PA) or Figure 8.4 on page 135 (12V PA). Do not fit the front panel
to the subrack.
3. Power up the test set-up and check the LEDs on the front panel of
the PA. These LEDs provide the following information about the
state of the PA:
■
steady green - the PA is powered up
■
flashing green - the PA has no application firmware loaded; use
the Service Kit to download the latest version of firmware,
recalibrate the PA, and repeat this step.
■
flashing red - one or more alarms have been generated; use the
Service Kit to find out more details about the alarms.
If the PA powers up, go to Task 2 . If it does not, go to “Visual Inspec-
tion” on page 144 .
Task 2 —
Check
Configuration and
Alarms
1. Fit the front panel to the subrack.
2. Run the Service Kit and connect to the base station. Once
connected to the base station, ensure that it is in Run Mode.
3. If you are testing a customer’s complete base station, read the base
station to load the PA’s configuration information into the Service
Kit.
If you have only the customer’s PA, and you are testing it in a test base
station, program the default profile into the test base station. Change
the default frequency as required.
4. Select Configure > Base Station > Channel Profiles. In the Edit
Channel Profile screen go to the Power Saving tab and check that:
■
the Tx Keyup time is 2ms
■
Sleep or Deep Sleep modes are not selected.