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4 4 4
FEATURE HAP
PAGE
5 OF
8
l39
.Switch power OFF
~.
•
Disconn~ct
wire 3 from PI8 on the
amplifier card.
.Switch power ON
m.
-Wait until the image appears .
• Set the TEST/NORMAL switch to TEST
and back to NORMAL.
-Hold down the AlT key. press the TEST
key, release both.
·Press keys / ENTER
-Decrease the brightness.
Are the blue characters now always
bright~
Y N
040
-Switch power OFF
~.
-Exchange the amplifier card.
GO TO MAP 0000. ENTRY POINT BB.
041
• Probe C2SD5 and press the selector
pen tip.
The DOWN light should come
on and remain on as long as the tip
is pressed.
Does this
occur~
Y N
042
.Exchange logic card G4 (then the
selector pen).
GO TO MAP DODD. ENTRY POINT BB.
043
-Exchange logic card C2.
GO TO MAP 0000. ENTRY POINT BB.
044
-Meter the voltage at TP 'J' on the
amplifier card.
Press and release the
selector pen tip.
Is the
volt~ge
always between 1.0 V dc
and 1.5 V
dc~
Y N
045
• Switch power OFF
~.
-Exchange the amplifier card.
GO TO MAP 0000. ENTRY POINT BB.
046
-Exchange logic card C2.
GO TO MAP 0000. ENTRY POINT BB.
47
(ENTRY POINT HHI
DO the blue characters change in
brightness as the brightness control is
turned?
Y N
Q
R
K
Q
R
4
HAP 0800-5
L
.Probe video card TP 'BG' (Blue Grid) •
See Fi gure 6-9.
-Turn the brightness control from
minimum to maximum.
The voltage measured should change
(approximately) from -70 V de to -20 V
dc.
Does this occur?
Y N
049
-Meter the amplifier card test point
'K' .
Expect +12 V (±1.5 Vdc).
Is the voltage good?
r i~OTO
MAP 0600. ENTRY POINT EE.
051
.S .. itch power OFF jg •
-Check the continuity of the Blue
Grid supply: P17B-l to P15-3 to TP
'BG' to P13-12.
-Check for short to ground.
See
Figure 6-7.
-Isolate to one of:
Ca) Wiring
(b)
Video card
(e) Amplifier card.
GO TO MAP 0000. ENTRY POINT BB.
052
.Switch power OFF
~.
.Exchange the video card then the CRT.
GO TO MAP 0000. ENTRY POINT BB.
53
·S .. itch power OFF
~.
-Exchange the amplifier card.
GO TO MAP 0000. ENTRY POINT BB.
054
.Press the light pen tip (do NOT point it
at the screen) .
White bars appear through all characters
on lines 2 and 3 of the test pattern.
-Set the bri
ghbles5
control to an
acceptable level.
.Press the pen against the white ?SEl PEN
field in line 2.
The field changes to >SEl PEN .
• Press the pen against the blue >SEl PEN
fi~ld
in line 3.
The field changes to ?SEl PEN.
-If
)(-f appears in
the indicator row,
press
RESET
and retry.
Did all occur as
expccted~
Y N
7 6
S T
04FEB81
HAP 0800-5
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