Fluke 93 - Page 137

CORRECTIVE MAINTENANCE
7
-
11
7. 1
.
$.4 Defa
uft signals measured in the digital Girovits.
The Digital
Ai
PCB
is provided with large I
megrated ctrcults. Fortesting the
board, tfie inpirt signals
and
output signals of the large Integrated circuits
are given in tables 7.2
up to
7.5.
and the
corresponding figures. These
signals can be used to check correct functioning
of the large Integrated
Circuits
on the digital A1 PCS.
All
measurements are made in
the default MASTER RESET condition
(start the measurements in the
SoopeMeter using MASTER RESET).
A MASTER
RESET is performed as follows:
1. Remove all
signals from the ScopeMeter.
2 . Turn off
the ScopeMeter
3. Hold down
the LCD key and press the ON/OFF
key sfmuttaneously. Two
beeps are
audible,
and
ail volatile memories (RAM with
battery backup) are reset. The ScopeMeter is
automatically set
to the Meter mode.
Use
another
oscilloscope with high
Input impedance and 1
0:1
probe to
measure the signals on the
integrated
circuits.
oi^ooauQOAOOaaaao
AD1
ADO
St
ALE/AlJy
INST
BUSWIDTM
CLKOUT
XTAL2
XTAL1
z
i-i
irt
Z <j
f
2^
s
•n
Figure 7.2
Microprocessor D 120
1
T2CLK
VSS
(0}
RCADY
P2.4
"WSL/WR
PWM
T2CAP P2
VPP
(+5V)
VSS
(0)
VSS
(o)
H50.3
VCC (-H5V)
VSS
(
0
)
H50.2
P2.6
PI-7
PT.6
PI.
5
MSO.l
HSO.O
HS0.3
VSS (Oj
WSD.4
ST6613
911114