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in the testing.
The FAULT ISOLATION column gives fault isolation instructions. It also
gives the parts, circuits, circuit blocks or assemblies that can be the
cause of the trouble given. We will refer to one of the fault isolation
procedures (E. and after) or the adjustment procedure (6.) in this column
if applicable.
T&FI-2
Page 159
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
Fault Isolation Table
ITEM SYMPTOM FAULT ISOLATION
3.C.(2)
(b)
You do not hear the 400-Hz hum
from the UUT or the fan above
the J1 connector does not turn.
Go to Fault Isolation Procedure for
Power Supply (E.).
3.C.(3)
(f)
The amplitude of the video
signal does not increase, but
stays unchanged.
There is an open-circuit fault
between the tester's VIDEO INPUT CH1
connector and the UUT's CH1 A2 card.
Find the fault and repair.
4.A.(4)
(d)
Communication error. Go to Fault Isolation Procedure for
Communication Error (F.).
4.A.(4)
(e)
The modulator status is "FAIL"
for one channel.
Go to Fault Isolation Procedure for
A2 Card Failure (H.).
4.A.(4)
(e)
The modulator status is "FAIL"
for two or more channels.
Go to Fault Isolation Procedure for
A1 Card (I.).
4.A.(4)
(e)
There is no RF carrier for one
channel.
Replace the A2 card for this channel
with that for a different channel.
If the RF carrier shows on this
channel, the fault is on the A2 card
(the power control circuit or RF
circuit).
If there is no change in the results,
the fault is possibly on the A5 card
(the related PC line).
4.B.(2)
thru (5)
The results are different for
the RF1, RF2, RF3 and RF4
outputs.
A3CB302 or its soldering is possibly
defective.
4.B.(2)
thru (5)
The RF output level is not in
the MIN-MAX limits for one
channel. The results are
almost the same for the RF1,
RF2, RF3 and RF4 outputs.
Adjust the RF level. Go to
Adjustments (6.).
T&FI-2
Page 160
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
Fault Isolation Table (Cont'd)
ITEM SYMPTOM FAULT ISOLATION
4.B.(2)
thru (5)
The RF output level is not in
the MIN-MAX limits for a group
of channels:
· Channels 1, 2 and 3
· Channels 4, 5 and 6
· Channels 7, 8 and 9
· Channels 10, 11 and 12.
The results are almost the same
for the RF1, RF2, RF3 and RF4
outputs.
The related power combiner on the A5
card or its soldering is possibly
defective.
4.B.(2)
thru (5)
There are no RF carriers for a
group of channels. The results
are the same for the RF1, RF2,
RF3 and RF4 outputs.
A1IC111 is possibly defective if
there are no carriers for CH1 thru
CH6 (PC01 thru PC06 outputs must be H
if A1IC111 is good).
A1IC112 is possibly defective if
there are no carriers for CH7 thru
CH12 (PC07 thru PC12 outputs must be
H if A1IC112 is good).
4.B.(2)
thru (5)
There are no RF carriers for
all channels. The results are
the same for the RF1, RF2, RF3
and RF4 outputs.
Examine the A4 card for +24V output.
If no +24V output, A4IC401 is
possibly defective. If there is a
+24V output, examine the A3 card to
find a fault.
4.B.(6) There is an RF carrier for one
channel.
The power control circuit on the A2
card for this channel (short-circuit
fault of A2Q208 or A2Q207) is
possibly defective if +5 V is applied
to A2VR202.
4.C.(1) The VMU tuner gives no video
output for one channel.
The video input circuit (A2IC201) on
the A2 card for this channel is
possibly defective.
4.C.(1)
(e)
The video input level is less
than 0.7 Vp-p or more than 1.3
Vp-p (RD-AA5002-23 or
RD-AA5002-25 only).
Incorrect position of the A2 cards.
For RD-AA5002-23, the 100-W input A2
card must be connected to the A5CN18
connector.
For RD-AA5002-25, the 100-W input A2
cards must be connected to the A5CN13
thru A5CN18 connectors.
T&FI-2
Page 161
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
Fault Isolation Table (Cont'd)
ITEM SYMPTOM FAULT ISOLATION
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(76)
