Heathkit H9 - Page 44

Pase4.
@
CONDITION
POSSIBLE
CAUSE
73. No
plot.
1.
Plot key not
pushed
in.
2.
No
plot
coincidence.
1C206,
lC209A, lC209B, lCzOgD,1C212,
tc219A.
3. Plot video. lC210B, lC208A,
lC218A.
4.
tczzlB, tc221?.
74.
Plot line
appears
in
wrong
place.
1.
2.
Plot
coincidence. 1C206, lC209A, lC209B, lC209D.
Plot inverters.
1C212, lC219A.
75.
No repeat
(characters
or cursor).
1. 1901.
2. Vn'
input to keyboard
open
3. D401.
4.
Repeat
Key.
76.
No cursor
reoeat.
1. D401.
2-
Q401.
3. R403.
77.
No relresh interrupt.
1. No refresh interrupt
signal. lC610C, P601-21,
5703-3.
2. Rear
panel
Baud switch not wired
correctlv for
>
600 baud.
3. tc705A, tc706B.
78.
Screen blinks
at
low
baud rates.
1.
Rear
panel
Baud
switch wired for
>
600
baud
2. tc705A.
79.
No hold
screen mode.
1. tc733c. rC733D.
tC739A
80. Locks
uo in hold
screen mode.
1.
tc739B. tC739D. tC739A.
tC739C
81. No transmit
page.
1. XP flip-flop not
being set. lC731C, lC731D, lC732C,lC732D.
2. 7C
oulse.
3.
No OB2XP load
pulse.
lC701A,
lC701B, lC704A, 1C702.
No
OB2
pulse
into 1C702.
4.
Count up not happening:
Duplex key in Full
Duplex
(pushed
in) instead
of
Half
Duplex
(released).
1c704.
tC725A,
lC719C
(fake
DAV).
82. Transmit
page
won't
stoo.
1. lc7259.
lC721A.
2.
Transmit
page
was started in the
hold screen mode. Press
and
release
the Scroll
or
Break
keys to
exit
the
transmit
page
mode.
83. No
end of line
bell.
1.
End
of
line
decoder. lC7168.
lC716C. lC718A. lC735C.
2.
Monostable 1C736,
R717,
C7'17.
3.
Speaker driver lC742A.
84. No
bell from
control G.
1. Bell
detector
on
the l/O
circuit board. lC617D,
1C614, 1C623.
2.
tc724B.
3. Monoslable
1C736, R717,
C717.
4.
Speaker driver
lC742A.
85.
Screen is
not erased when
the Terminal
is
lurned on. 1.
Power
up reset.
Q701
,
lC717A, lC717B, lC717C,
lC717D,
lc717E, D701
.
2.
Erase
circuit. lC715A.
lC723A.
86. Cursor
is moving
when
the Terminal
is turned
on.
'1
.
Terminal is in
transmit
page
mode.
2. XP
flip{lop
(1C731C,
lC731D)
did not
get
reset
by the
power
up
reset.