Tait TB8100 Service Manual page 236

Task 2 —
Check Standby
Power Supply Card
(if fitted)
236 Power Management Unit Fault Finding
Once you have established that the DC converter is working correctly (the
PA output is 28VDC and the LEDs are indicating normal operation), you
can plug in and test the standby power supply card.
Note
The exact voltage levels at which the PMU starts and shuts down
(as the input voltage changes) will depend on how the PMU has
been configured using the Service Kit (Configure > Base Station
> Miscellaneous > Power configuration). Refer to the Service Kit
documentation for more details.
1. Set up the PMU as described in
2. Plug the standby power supply card into the DC converter board, as
shown in Figure
3. Connect the correct DC supply to the input of the DC converter.
The standby supply now powers the microprocessor, and switches off
the DC converter until the microprocessor switches it on again.
4. Measure the voltage at either PA output connector. The output
voltage should be 28VDC. If it is, go to
Step 5.
5. Check that the DC converter is not in battery protection mode (red
and green LEDs flashing slowly). If this is the case, increase the DC
input voltage until it is in the normal operating voltage range.
6. Check that the reciter output is approximately 28.6VDC. If it is, go
to Step 7. If it is not, return to
7. Reduce the DC input voltage to approximately 10.5VDC (21VDC)
[42VDC] and wait for 30 seconds. Both the reciter and PA outputs
should now be disabled, and both indicator LEDs should flash slowly.
The DC converter is now in battery protection mode. If it is, go to
Task 8. If it is not, replace the standby power supply card and repeat
this task. If the fault is still present, go to
8. Increase the input voltage to 13VDC (26VDC) [52VDC], and check
that the reciter and PA output voltages return to normal. If they do
not, go to Task
the PMU is not fitted with an AC module, go to
page 247.
Task
13.8.
Task 1.
3. If they do, go to "AC Module" on page
© Tait Electronics Limited September 2006
1.
Step 6. If it is not, go to
Task 3.
"Final Tasks" on
TB8100 Service Manual
240. If