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1 122
POWER MAP
PAGE
3 OF
I
020
-Switch power OFF
~.
-Unseat the analog card.
-See Figure 6-8 and Figure 3-1.
-Check the +5v cable from the logic
A3 connector to the analog card
P4-34 for continuity and short
circuit to ground.
• If no problem is found exchange the
analog card.
GO TO MAP 0000, ENTRY POINT BB.
021
-See Figure 6-8 and Figure 3-1 and the
table below to check the supplies to
the analog card and the LED
Ind; cators.
VOL TAGE.
LOGIC ANALOG
TOL. GATE
Wire
+5 Vdc
0.5V B2J03
34
-5 Vdc
0.5V B2G06
29
+8.5Vdc 0.9V B2G11
35
o
V
....
B2J08
30
-Switch power OFF
~.
-Check continuity:-
Analog P4-10 to LED P12-6.
Analog P4-34 to LED P12-7.
Did you find a problem?
Y N
022
CARD P4
TP
37
5
36
10
-Exchange the anal09 card (then the
power supply card).
GO TO MAP 0000, ENTRY POINT BB.
023
-Trace and repair wiring
if
possible
or exchange any failing FRU.
GO TO MAP 0000, ENTRY POINT BB.
024
GO TO STEP 025,
ENTRY POINT BB.
25
(ENTRY POINT BBl
-Switch power OFF
~
and connect a meter to
+5 V on the logic board.
(0 V
=
B2008, +5 V
=
82D03).
There now follows a sequence of FRU
disconnecting and reconnecting to find
which FRU is
ov~rloading
th~
power supply.
CAUTION
When investigating with FRUs
disconnected:-
-Do NOT switch power ON for more than 5
minutes.
-Do NOT leave the 3279 unattended with
power ON.
Remember POWER should not be switched back
ON until 10 seconds after POWER OFF.
(Step 025 continues)
MAP 0200-3
(Step 025 continued)
-Disconnect the keyboard.
-Switch power ON
m.
Is the +5 V supply npw present (between
+4.5
V and
+5.5
Vl?
Y N
5
H
026
-Leave the keyboard disconnected.
-Switch power OFF
~
.
-~isconnect
the video card plugs P14 and
P16.
See Figure' 1-4,
-Switch power ON
m.
~
~s
N the +5 V supply now present1, "
027
-Switch power OFF
~.
-Reconnect the video card connectors
P14
and
P16.
-Disconnect amplifier card plug
P18.
See Figure
1-4.
-Switch power ON
m.
Is the +5 V supply now present?
Y N
028
-Switch power OFF
~.
-Reconnect amplifier card connector
P18.
-Disconnect amplifier card
connectors P17A and P17B.
-Switch power
ON
m.
IS the +5 V supply now present?
Y N
029
-Switch power OFF
~.
-Reconnect amplifier card
connectors P17A and P17B.
-Di5conn~ct
the logic gate
A3
cable.
-Switch power
ON
m.
Is the +5 V supply now present?
Y N
5 5 4 4
K L M N
04FEB81
MAP 0200-3
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