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5.C. The picture on the video
monitor has diagonal stripes,
shows incorrect colors, etc.
There are many causes for this type
of fault, and fault isolation is not
easy without special instruments.
5.D.(6) You do not hear a "click". Push the F6 key two or four times to
make sure that there is no "click".
If there is no "click", make sure
that the TG CONT signal at the
A8CN508 connector is L, then examine
the A8Q504/A8IC504 circuit to find a
fault.
5.D.(6),
(7)
There is no video output and no
picture on the video monitor.
Examine the video generator circuit
on the A8 card to find a fault. If
the white raster video output goes to
A8RL501, replace A8RL501.
5.D.(7) The video output level is less
than 0.75 Vp-p or more than
0.95 Vp-p.
Adjust A8VR501 and A8VR502 (first
type A8 card, Figure 110) or A8VR501
(second type A8 card, Figure 110A).
Go to Adjustments (7.).
5.E.(3) You do not hear a "click". Push the F6 key two or four times to
make sure that there is no "click".
If there is no "click", examine the
A1IC114 output. A1IC114 is possibly
defective if it is L. If A1IC114
output is H, A5RL1 is possibly
defective.
5.E.(3) You hear a "click", but there
is no picture on the video
monitor.
A5RL1 is possibly defective.
5.F.(1)
thru (4)
The results are different for
the RF1, RF2, RF3 and RF4
outputs.
A3CB302 or its soldering is possibly
defective.
5.F.(1)
thru (4)
The RF output level is not in
the specified 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 (7.).
Page 138.08
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
5.F.(1)
thru (4)
The RF output level is not in
the specified 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.
5.F.(1)
thru (4)
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).
5.F.(1)
thru (4)
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.
5.F.(5) 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.
Page 138.09
Feb 20/2002
Matsushita Avionics Systems Corporation
COMPONENT MAINTENANCE MANUAL
PART NUMBER RD-AA5002 SERIES
23-32-47
CAUTION: DO NOT USE THE OSCILLOSCOPE FOR FAULT ISOLATION OF THE PRIMARY AND
SECONDARY CIRCUITS OF T1 AND T2, OR A SHORT-CIRCUIT FAULT WILL
OCCUR THROUGH THE OSCILLOSCOPE GROUND.
D. Fault Isolation Procedure for Power Supply (A6 Card, T1, T2 and A4 Card)
NEXT STEP IF
STEP CHECK/POSSIBLE FAULT
YES NO
D-1 Do you hear the 400-Hz hum from the UUT? D-3 D-2
D-2 Do a continuity check of the AC power lines between the
J1 and A6CN2 connectors to find a fault. If the AC power
lines are good, examine A6F1 and A6F2. If they are open,
examine the circuit after them for a short-circuit fault
and repair, then replace them. --- ---
D-3 Does the fan above the J1 connector turn? D-5 D-4
D-4 Examine the A4 card for -9V output at A4CN402. If no -9V
output, examine the +9V power circuit on the A4 card to
find a fault. If there is a -9V output, replace the fan
assembly. --- ---
D-5 Examine the A4 card for +8V, +32V and +24V outputs to
find a fault. --- ---
Page 138.10
Feb 20/2002
Matsushita Avionics Systems Corporation
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COMPONENT MAINTENANCE MANUAL Video Modulator Unit (VMU)(40)
