Test Equipment; Troubleshooting - OKIDATA OKIMATE 20 Technical Service Data

TEST
EQUIPMENT
Test
Equipment
listed
by Manufacturer
illustrates typical or
equivalent
equipment used
by
SAMS' Engineers
to
obtain
measurements
and
is
compatible with
most
types
used
by
field
service technicians.
TEST
EQUIPMENT (COMPUTERFACTS)
Ecjuipmerrt
B & K Precision
Equipment No.
Sencore
)
Equipment No.
Notes
OSCILLOSCOPE
1570A,1590A,1596
SC61
LOGIC
PROBE DP51.DP21
LOGIC PULSER
DP101.DP31
DIGITAL
VOM
2830,2806
DVM37,DVM56,SC61
ANALOG VOM
277,111,116
ISOLATION
TRANSFORMER
TR1 10,1604,1653,1655
PR5
7
FREQUENCY COUNTER
1803,1805
FC71.SC61
COLOR
BAR GENERATOR
1211A.1251, 1260,1249
CG25.VA62
RGB GENERATOR
1260,1249
FUNCTION
GENERATOR
3020,3011,3030
HI-VOLTAGE
PROBE
VOM/DMM
Accessory probes
HV-44
PR-28(HV)
HP200
TEMPERATURE PROBE
TP-28JP-30
CRT ANALYZER
467,470
CR70
DIGITAL
IC
TESTER
560,550,552
CAPACITANCE ANALYZER
LC53,LC75,LC76
LC77
INDUCTANCE ANALYZER
LC53,LC75,LC76
LC77
o
w
4*
s
o
o
m
POWER SUPPLY
NOTE:
Use
an
step down contro
TROUBLESHOOTING
w
ii\3
isolation
transformer with
when servicing power supply-
Disconnect Connector CN9 from
avoid possible
damage to Pr
voltage that may be
produced
Power Supply.
Dr
i
ver
Board
to
nter
from high
while
servicing
NOTE:
Power Supply will not
operate properly
if
Connector CN9
is
disconnected from
Driver
Board unless
the proper bias
and
load
Resis-
tors are connected to Connector CN9.
Connect
a
390 ohms 1/2W bias
Resistor from pin
3
to pin 4
and 4700 ohms
1/2W
bias Resistor
from pin
3
to pin
5
of
Connector
CN9.
Also
connect
a
30
ohms, 10W load
Resistor from pin
1
to pin
6
and
a
10
ohms, 10W load
Resistor
from pin
5
to pin 6 of
Connector CN9.
POWER SUPPLY DEAD
Check Fuse
F.
If
fuse
is
open,
check for
possible shorts at
Bridge Rectifier
S
1 1
and
Oscillator Transistor
(01).
If
fuse
is
good,
apply AC power and check for 120V
AC
at
the AC
input pins of SI1.
If
120V AC
is
missing,
check Resistor
R1
,
Coil
LI
and Switch
SW.
If
120V
AC
is
present, check
for 167V at the cath-
ode
of SIT-
If
167V
is
missing, check
S
1
1
-
If
167V
is
present,
check waveform at base
of
Oscillator
Transistor
(01).
If
waveform
is
missing, check
voltages
and
components asso-
ciated with
01
and
Regulator Transistor (Q2)
and check Transformer
TR.
The 14.4V
Source
is
missing
Diode SI2,
Capacitor
C11
and
on
Transformer TR from pin
6
tinuity.
,
Check Coi
I
L2,
check the winding
to pin
7
for con-
O
>
©
2
o
The 14.6V
source
is
not correct and adjusting
voltage Adjust Control VR has no
affect.
Check
voltage
and
components associated
with
Error Amp
Transistor
(03)
and
Optoisolator
(PC).
Regulated 5.0V source
is
not
correct or miss-
ing.
Check
5V
Regulator
IC
(A),
Diode
SI3,
Capacitors
CI
4
and
CI 5
and
check winding
on
Transformer TR from pin
8
to pin 9 for
continu-
ity.
The
-9.0V
source
is
missing at
pin
7
of
Connector CN9 on Driver
Board. Check
Diode
Si4,
Capacitor
C16
and Resistor R15
on
Power
Supply
Board and Zener Diode
D1
and Capacitor
C6 on Interface Board.
The 9.0V
source
is
missing on
the Interface
Board (cathode
of
Zener Diode
D2).
Check
Zener Diode D2 and the
voltages and components
associated
with Regulator Transistor
(TR1)
and
Switch Transistor (TR3).on Interface Board.