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START/RESTART HAP 0000
PAGE
1 OF
2
ENTRY POINTS
FROM
ENTER THIS MAP
MAP
ENTRY
PAGE
STEP
NUMBER
POINT
NU~lBER
NmlBER
0100
BB
2
010
0200
BB
2
010
0300
BB
2
010
0400
BB
2
010
0500
BB
2
010
0600
BB
2
010
0700
BB
2
010
0800
A
1
001
0800
BB
2
010
0900
BB
2
010
1000
BB
2
010
001
(ENTRY POINT Al
DANGER
When thQ power ON/OFF switch is ON
m~
the
following are connected directly to the
mainline power:-
-The front panel fuse
&
switch,
-The degauss coil.
-Parts of the power supply card and
-The twisted-pair connection from P3
pins 8 and 9 (on the power supply card)
to the analog card (P71.
eBe careful when measuring voltages in
these areas.
-Switch power OFF
~
and remove the power
cord from the mainline power socket
before such actions
a5:-
-disassembling,
-inspecting for failures,
-making resistance measurements, etc.
-Start here to isolate any failure on the
IBM 3279 display station.
-Before exchanging any FRU take note of
the comments in MIM section 2.3.
-Ensure that
th~
3279 is
corr~ctly
connected to a working Control Unit with
correct color setup code.
-Start problem determination at the
General Failure Index (MIM section 2.2).
If the problem is described in the GFI,
perform the associated actions.
-If the problem is not described, continue
with this MAP.
Is the
p~ob1em repai~ed
by using the GFI?
Y N
002
Does the power supply fail when the 3279
is in use
o~
being
se~viccd?
(Lamp 1
changes from ON to OFF -
it may flash a
few times.)
Y N
222
ABC
Copyright IBM Corp 1981
HAP 0000-1
EXIT POINTS
EXIT THIS MAP
TO
PAGE
STEP
MAP
ENTRY
NUMBER
NUrlBER
NUMBER
POINT
2
005
0100
A
2
013
0100
A
2
008
0200
FF
2
007
0700
A
2
006
1000
A
GENERAL LOGIC PROBE.
To use the
Gen~ral
logic Probe (P.N.
453212), set the switches
as
fol10ws:-
TECHNOLOGY ... MULTI
LATCH .....•.• NONE
GATE REF ..... GND
Power
up
the probe
by
connecting:-
Black wire to any
D08
pin (ground)
&
Red wire to any
003
pin
(+5V).
Test by probing on
008
&
003
pins.
OSCILLOSCOPE.
If using an oscilloscope in place of a
G.l.P.,
interpret the indicators
as
follows:-
The GREEN light ON represents a voltage of
less
than
+
1 V .•
The RED light ON
r~present5
a voltage of
greater than +2V.
Both lights
ON
indicates a waveform
pulsing
beyond
both these limits.
04FEB81
HAP 0000-1
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