Figure 13.7 Location Of Test Points On The Dc Control Card - Tait TB8100 Service Manual

Task 3 —
Check DC Control
Card
Figure 13.7 Location of test points on the DC control card
PL2
1
PL2 ground
Task 4 —
Check Plug-in Cards
with Another DC
Converter
TB8100 Service Manual
© Tait Electronics Limited September 2006
1. Check that VAUX is present on pin 6 of PL1 (VAUX line), as shown
in Figure 13.7. If it is, go to
2. Check that the DC-Stop line is low on pin 1 of PL2. If it is, go to
Step 3. If it is not, check for short circuits around PL2. Carry out
any necessary repairs and repeat this step. If the fault is still present,
go to Task 4.
3. Check for a PWM signal on pin 5 and pin 7 of PL1. If it is present,
go to "DC Converter with Microprocessor Control" on page
it is not, replace the DC control card and repeat this step. If the fault
is still present, go to
Note
There are different grounds (signal return paths) associated with
each connector. You must use the correct ground to make mean-
ingful measurements.
PL1
7 6 5
PL1 ground
If the DC converter still fails to produce an output after testing the control
cards as described above, the DC converter board may be faulty.
1. Remove the plug-in cards from the DC converter under test and fit
them to another DC converter which is known to work.
2. If this second DC converter works correctly, the DC converter under
test is faulty.
3. Fit a new DC module to the PMU under test, reassemble the PMU,
and go to "Final Tasks" on page
Step 2. If it is not, go to
Task 4.
247.
Power Management Unit Fault Finding
Task 4.
234. If
bottom side of card shown
233