Star Tech Journal
Issue: 1997-March - Vol 19 Issue 1 - Page 16
STAR*TEcH
Journal
Surfin' the
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Journal's Home Page on
the World Wide Web.
You can reach Star*Tech
Journal through the
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ST J TO RELEASE
PINBALL V2
Star Tech Journal, in the process of
updating it's entire Technical Library,
will soon release the follow-up to it's
very successful "Pinball Repair &
Maintenance" service manual.
Pinball V2 will pick up where the
original left off and will include all of
the best service tips, troubleshoot-
ing methods, parts subs, modifica-
tions and symptom/solution fixes for
nearly every pinball game manufac-
tured during the last 5 years.
Priced at $49. Order prepaid or COD
from Star Tech Journal, PO Box 35,
Medford, NJ 08055. Ph: 609/654-
5544. Fax: 609/654-1441.
March 1997
Work Bench
... continued from page 10
pretty well for that. Y'know, I
don't miss coin-op laundry a bit.
Clamp-on current probes or
adapters are probably of use only
occasionally in our business, but
they can help check the draw on
big motors (or big vending gear),
or they can help diagnose power
problems in the arcade. You
might have to verify that the
twenty amp breaker that keeps
popping is actually carrying
twenty amps. Then there is the
location owner who asks you to
check out his air conditioner "as
long as you are here.'' One item
I would consider is the high volt-
age probe. Rated to 40K volts, it
lets you measure the high volt-
age on your picture tubes for
troubleshooting there. If you
have a screen expecting 4000 to
8000 volts, what else could you
measure it with? The high volt-
age probe is basically a well in-
sulated probe with a 1000 to 1
voltage divider within. If you
want to spend a hundred bucks
you can also find stand alone HV
probes that have a self contained
meter or readout.
On to other things. About the
most demanding measurement
we make is the 5 volt adjustment
to a logic board. To read that volt-
age within 1 % is to get within 0.05
volt, 0.1 % represents 5 millivolts.
Don't forget how the last couple
digits dance around in response
to the ever changing resistance
between your probe tip and the
connection. With that in mind, is
it really worth it to pay extra for
a meter to get an additional tenth
of a percent accuracy, which rep-
resents only a few millivolts?
Same with the readout. The
higher the accuracy the smaller
the increments it can measure.
The smaller the increments, the
more digits needed in the display.
What is the point. What does
5.12435687 volts tell me that 5.12
doesn't? In an engineering lab
maybe a lot. In the field, work-
ing on a pinball, nothing. Don't
pay an extra hundred dollars just
for accuracy/resolution, remem-
ber you can lose or step on a
$400 meter as easily as you can
a $200 meter.
Autoranging - I like it. Before you
buy a meter with autoranging,
check out the ranging speed.
Some meters, mostly cheap ones,
are
so
slow
they
just...drive ... you ... nuts. Good
meters will shift a few times a sec-
ond. In resistance mode, short
the leads then open them. Each
time, the meter will shift through
its ranges from end to end. How
long does it take? While we are
here, the same applies to display
update rate. Most reasonable
meters now update several times
a second, but some are very slow,
and believe me it gets annoying.
You really don't want a meter that
takes two or three seconds to
settle on each measurement.
I just saw a new "green" meter.
It had the usual features, but it
doesn't run on batteries. It has a
couple large value capacitors that
hold enough charge to run the
... continued on page 20
Journal
Surfin' the
Internet?
Visit Star*Tech
Journal's Home Page on
the World Wide Web.
You can reach Star*Tech
Journal through the
''Information Highway''
also known as the
Internet.
Leave email addressed
to:
ST J TO RELEASE
PINBALL V2
Star Tech Journal, in the process of
updating it's entire Technical Library,
will soon release the follow-up to it's
very successful "Pinball Repair &
Maintenance" service manual.
Pinball V2 will pick up where the
original left off and will include all of
the best service tips, troubleshoot-
ing methods, parts subs, modifica-
tions and symptom/solution fixes for
nearly every pinball game manufac-
tured during the last 5 years.
Priced at $49. Order prepaid or COD
from Star Tech Journal, PO Box 35,
Medford, NJ 08055. Ph: 609/654-
5544. Fax: 609/654-1441.
March 1997
Work Bench
... continued from page 10
pretty well for that. Y'know, I
don't miss coin-op laundry a bit.
Clamp-on current probes or
adapters are probably of use only
occasionally in our business, but
they can help check the draw on
big motors (or big vending gear),
or they can help diagnose power
problems in the arcade. You
might have to verify that the
twenty amp breaker that keeps
popping is actually carrying
twenty amps. Then there is the
location owner who asks you to
check out his air conditioner "as
long as you are here.'' One item
I would consider is the high volt-
age probe. Rated to 40K volts, it
lets you measure the high volt-
age on your picture tubes for
troubleshooting there. If you
have a screen expecting 4000 to
8000 volts, what else could you
measure it with? The high volt-
age probe is basically a well in-
sulated probe with a 1000 to 1
voltage divider within. If you
want to spend a hundred bucks
you can also find stand alone HV
probes that have a self contained
meter or readout.
On to other things. About the
most demanding measurement
we make is the 5 volt adjustment
to a logic board. To read that volt-
age within 1 % is to get within 0.05
volt, 0.1 % represents 5 millivolts.
Don't forget how the last couple
digits dance around in response
to the ever changing resistance
between your probe tip and the
connection. With that in mind, is
it really worth it to pay extra for
a meter to get an additional tenth
of a percent accuracy, which rep-
resents only a few millivolts?
Same with the readout. The
higher the accuracy the smaller
the increments it can measure.
The smaller the increments, the
more digits needed in the display.
What is the point. What does
5.12435687 volts tell me that 5.12
doesn't? In an engineering lab
maybe a lot. In the field, work-
ing on a pinball, nothing. Don't
pay an extra hundred dollars just
for accuracy/resolution, remem-
ber you can lose or step on a
$400 meter as easily as you can
a $200 meter.
Autoranging - I like it. Before you
buy a meter with autoranging,
check out the ranging speed.
Some meters, mostly cheap ones,
are
so
slow
they
just...drive ... you ... nuts. Good
meters will shift a few times a sec-
ond. In resistance mode, short
the leads then open them. Each
time, the meter will shift through
its ranges from end to end. How
long does it take? While we are
here, the same applies to display
update rate. Most reasonable
meters now update several times
a second, but some are very slow,
and believe me it gets annoying.
You really don't want a meter that
takes two or three seconds to
settle on each measurement.
I just saw a new "green" meter.
It had the usual features, but it
doesn't run on batteries. It has a
couple large value capacitors that
hold enough charge to run the
... continued on page 20
Future scanning projects are planned by the International Arcade Museum Library (IAML).