Fluke 93 - Page 152

7-26
CORRECTIVE MAINTENANCE
1^
2
1
SRG5
T
1
>
Cl
>
C2/-^
II Ci
10
20
30
1 1
12
3D
T3
1 4
5
4
5
6
7
A
HCT !65 ST6625
Figure 7. S Keyboard decoders
D1601/02/02f04/0$
D3
07
5T6622
9T11
U
Table
7.6 Signals measured on keyboard
decoders D 1601/02/03/04/06.
Logic 0*0V Logic
1=+5V
Comp Name
Scope Freq. Data Description
CIrc/IC
H/L/A
D1601/D1 602/D1603/D1
604/DI 606
1 FRONT-LATCh/GI
Unstable
34 Hz A
FRONT LATCH signal
2 FRONT-CLOCK/>1
Unstable
775 Hz A FRONT
CLOCK signal
3 CURSOR2-U...
D1601
0 H CURS0R2-Left
key
B-MOVE-UP/...
D1602
0
H
Channel
B-MOVE-UP key
CURSOR1-R/...
D1603
0 H
CURSOR1 -Right key
TlME-ns/...
D1604
0 H TIME-ns key
LCD/...
D1606
0 H Liquid
Crystal Display key
4 CURSOR1-L/...
0 H
CURSOR1 -Left key
TlME-s/...
0 H TlME-s
key
SOFT-5/...
0 H Soft key
-5
A-MOVE-UPy...
0 H Channei A-MOVE-UP
key
SPECIAL/....
0 H SPECIAL FUNCTion
key
5 SOFT-4/...
0 H Soft key
^4
A-mV/...
0 H Channel
A-mV key
SOFT-3/...
0 H
Soft key
-3
B-AC/DC/...
0 H Channel
6-
AC/DC/GROUND
key
HOLD/RUN/...
0 H HOLD/RUN