Classic Mode

Star Tech Journal

Issue: 1987-June - Vol 9 Issue 4

STAR*TECH J9urnel
The "OCTOPUS" Analyzer (Part 1)
By William F.aton
Nickels & Dimes Inc.
Laguna Hills, California
June 1987
analyzer are all cOIIIIIOn items. Since all
the parts are noncritical, they may be
substituted. Most items can be scrounged
from the junk box.
For those of you who have considered a
$100.00+ "corrp:ment analyzer" for your
oscilloscope, this simple project may make
your day. For soire of you ex-military
techs, this piece of equipnent is probably
already on your bench. This project can be
completed in about one hour with about two
to three dollars in parts!
The comp:ment analyzer or "octopus" is an
electronic device used to troubleshoot
deenergized circuit board asse:rrblies. It
is designed for easy construction and to
locate defective cornp:>nents on circuit
boards quickly and safely without the
necessity of removing components from the
circuit. Used along with any standard dual
~ race oscilloscope, the comp:>nent analyzer
provides a visual display of component
condition.
A DELICATE TEST
The component analyzer is designed to
quickly test delicate COIIlfX)nents. It does
not deliver more than 1.0 milliamps of
a-c. It energizes COIIlfX)nents during test,
without removal of cornp:>nents. By using
a.c., the analyzer will simulate more
accurately the operating conditions.
VERSATILE
While the COIIlfX)nent analyzer tests all
cornp:>nents for shorts and opens, it can
also be used to display junctions on
transistors and diodes. Moreover,
utilizing Lissajous and combination
patterns on the oscilloscope, the
cornp:>nent analyzer easily analyzes
integrated circuits and reactive
cornp:>nents (capacitors and inductors) that
defy ohrmneter analysis. It is useful also
in checking continuity (switches, fuses,
. amps, printed wiring, etc.).
(9)
Y
OUTPUT
C:, iJC.
TO
x 'scoPE
l?Eo
PbhE
·~I..L. ~E.S1.$TOllS Y-, ..l/U'T
f";t
I
Low voltage and low current are necessary
for protection of delicate comp:>nents; the
1,000 ohm resistor placed across 1 volt
assures the safe current of 1.0 milliamp.
A center tapped 6.3 volt filanent
transformer is COI11I10nly used. It delivers
about 3.0 volts a.c. (from center tap),
which is dropped by resistors to 1.0 volt.
If you can't
transformer,
273-1385 and
to reduce it
find a 6 volt center tapped
you can use a Radio Shack
use a voltage divider network
down to 3 volts.
'!he leads should be color coded (black for
the ground and red for the hot lead) and
should be needle tipped or filed to a
sharp p:>int to penetrate the coating on
soire printed circuit boards. (Dull leads
usually fail to make proper contact.)
To prevent lead hunting, the leads should
be permanently attached to the comp:>nent
analyzer. BNC connector jacks are used for
the Y and X outputs or the cables may be
permanently fastened.
CONSTRUCTION
As shown in figure 1, the few parts that
go into the construction of the component
ACCESSORIES
A fuse, on/off switch, and pilot light may
STAR*TECH Journal
be added to the primary circuit if
desired.
The project can be enclosed in any
suitable hobby oox, you may want to drill
a few holes for ventilation. You can also
add a few resistors with a switch to
increase or decrease the output and
provide selectable ranges. I have used the
"basic model" described for many years
with great results.
TFST SET-UP
M-len the tester is to be used, its Xis
connected to the oscilloscope's
horizontal, or X input and its Y to the
oscilloscope's vertical, or Y input. 'Ihe
oscilloscope should be placed in the X-Y
mode. The vertical and horizontal gain
controls on the oscilloscope should be
adjusted to prevent trace ends from going
off the screen.
TEST PROCID.JRE
Rerrove :rower to ooard under test. If the
printed circuit or chassis under test is
grounded, the black lead should be
attached to the ground end of the
comp:ments.
Next month I'll describe how to use the
analyzer to constructively repair
equipnent.
June 1987 (10)
TROUBLESHOOTING ELECTROHOME
WELLS GARDNER MONITORS
&
troubleshooting manual covering the
I A servicing
of the most popular color video
monitors used in the Coin-Operated
Amusement Industry, has just been
published by STAR*TECH JOURNAL.
This very thorough and detailed manual
covers every aspect of monitor repair
including: Power Supply Section - symptoms
and solutions. CRT Construction and
Operation -brightness problems end
solutions. Deflection Circuitry -sync
circuit description end troubleshooting.
Color Problems -including degaussing,
purity, white balance end convergence
adjustments.
Troubleshooting Electrohome & Wells
Gardner Monitors is priced at $19.95 (US)
plus $2.50 shipping.
Distributed by STAR*TECH JOURNAL.
POB 1065, Merchantville, NJ 08109.
SERVICE MANUAL
Instructional and reference manual
entitled ELECTRONIC GAME REPAIR covering
such subjects as: Basic Electronics,
Semiconductors, Video Game Systems,
Electronic Pinball Systems,
Troubleshooting Techniques, Tools end Test
Equipment, Schematic Reading and more.
This 8-1/2 11 x 11" manual contains 65 pages
of technical information for the servicing
of electronic amusement games and is
priced et $24.95 plus $2.50 shipping.
Distributed by STAR*TECH JOURNAL.
POB 1065, Merchantville, NJ 08109.
VOLUMES/ISSUES
Some beck issues end complete volumes
remain in our inventory. Complete Volumes:
$42 ($US). Single Issues: $5 ($US).
*
INSIDE SW1TCHIKi
~
*** Send self-addressed stamped ($0.39)
envelope (#10 or Larger) for complete
index of ell articles covered since Mer79.
(Part 4)
by James Beck of Greater Southern
Distributing Co., Atlanta, Georgia will be
seen next month. DJe to the late arrival
of data specs from Sharp Mfg. on their
control logic ICs, this roonth's
installnent was held-up beyond our
deadline. 'Ihe series will continue in the
next issue with coverage of the Control
Logic Circuitry and future articles will
include Troubleshooting Methods for these
switching-type power supplies.
Availability: Complete Volumes (twelve
issues bound under one cover);
#1 ( Ma r79-Feb80),
#2 (Mer80-Feb81),
#3 (Mar81-Feb82),
#4 (Mar82-Feb83).
******************************************
ISSUE PACKAGES@ $42 (US).
Pkgf5B1 May84, Jun84, Jul84, Aug84,
Nov/Oec84, Jun85, Jul85, Aug85,
Sep85, Oct85, Nov85, Oec85,
Pkgf78; Jan86, Feb86, Mar86, Apr86,
May86, Jun86, Jul86, Aug86,
Sep86, Oct86, Novas, Oec86,

Download Page 9: PDF File | Image

Download Page 10 PDF File | Image

Future scanning projects are planned by the International Arcade Museum Library (IAML).

Pro Tip: You can flip pages on the issue easily by using the left and right arrow keys on your keyboard.