525,2-10
B.
TROUBLESHOOTING (Contd)
2.
50Kl22
UNITIZED KEYBOARD TROUBLESHOOTING
TROUBLESHOOTING GUIDE
QUESTION
YES
1.
Do any indicator keys fail to light?
Go to
la.
la.
Is
-12 V
present on pin
4
of LED of
Go
to lb.
keyswitch in question?
lb.
Is
-10 V
present on pin 3 of LED of
Go
to
2.
keyswitch in question?
2.
Do operational control keys operate
Go to
3.
correctly under
all
conditions?
2a.
Is
+5 V
present on circuit card cable
Go to
2b.
connection of keyswitch in ques-
tion when keyswitch is open
(released up position)?
2b.
Is
0 V
present on circuit card cable
Go
to
3.
connection of keyswitch in ques-
tion when keyswitch is closed
(depressed down position)?
3.
Are all characters printed when
Go to
4.
"DATA" keys are depressed?
3a.
Are supply voltages present on
Go
to 3b.
circuit card cable connections?
3b.
Are supply voltages present at inputs
Go to
4.
to MLBl?
4.
Is clock pulse present and correct
Go to
5.
at pin
11
of MLBl?
·
5.
With REPT key and keyswitch in
Check
Pl07,
pin
6
question depressed, is serial data
for continuity.
present on pin
9
of MLBl?
Go to
6.
6.
Are drive pulses present on pins
Go
to 7.
16, 17, 18, 19
and
20
of MLBl?
7.
Are sense pulses present on input
Go
to 7b.
to MLBl of keyswitch in ques-
tion when it is closed (depressed
down position)?
7b.
Are sense pulses present on sense
Replace keyswitch in
line inputs to MLBl with no keys
question.
depressed?
NO
Go to
2.
Check circuit card or
cable for open circuit.
Check cable for an open
circuit.
Go to 2a.
Check cable for an open
circuit.
Check
Pl07,
pin
4
for
an open circuit.
Go to
3a.
Check cable for an open
circuit.
Check circuit
card
for an
open circuit. Check diode
Cl.
Check cable and circuit
card for
an
open circuit.
Replace MLBl.
Replace MLBl.
Check circuit
card
for an
open circuit.
Replace keyswitch in
question.
Go
to 8.
•
/
•
Содержание 43K001/AAA
Страница 1: ...Used in 42143 BASIC TERMINALS j j I I I...
Страница 2: ...1978 1980 1981 1982 and 1983 by Teletype Corporation All rights reserved Printed in U S A...
Страница 4: ......
Страница 8: ......
Страница 10: ......
Страница 52: ......
Страница 62: ......
Страница 69: ...L 9 gzg IVONVW OSIO m I I t r I I I I I I OI 9Sl0Zv Z OvZl9l...
Страница 81: ......
