5H[]P. ..
I f an video i pre 'ent at all
say, if the core IS
present, but not the net r the paddle
then
video i pre ent to the tv, but the problem is on
the computer board.
If the 5 micro ec. horizontal ynchronizing
pul e are pre ent from the I gic board, they will
o perate the tv sw e p ircuits and the white lamp of
tatives readil agree that it is possi ble to find 90
per cent of the po sib le printed circuit board
malfunctions without the following item, if an
game c mpanie desire a complcte arra of trouble
-shooting cquipment, they recommend:
probe and the tv can't be locked in horizontall ,
then the tv is bad.
Atari recommend u ing the Kurz-Kasch LP-520
probe for testing the audio output of computer
boards. Since the audio signal is a 5v logic signal,
the red lamp of th probe will illuminate when
audio i pre ent.
Atari will provide free video probes through
their customer servic' department in Los Gatos,
a liforn ia. The video probe is a very imple, but
u eful device, con i ·ting of two tc ·t c lips, a length
of rubber-coated test-lead wire and a 4.7K one-
fourth watt carbon resistor. Video probes may also
be assembled from standard components available
at all electronic supply hou es.
To u e the video probe, ana h one clip to the
negative (-) side of the 10 uf video coupli,ig
capacitor found ncar position 9 on the printed
circuit board and clip the other end to the desired
signal test points. The video probe allow ' the
desired signal to be displayed on the tv monitor
creen.
Alth ough even Atari customer 'crvice represen -
tative readi ly agree that it i possible to find 90 C
of the possible printed circuit board malfunction s
without the following item, if any game om -
panic ' desire a com plete arra of trouble- 'hooting
etluipment, they recommend:
- Hewl ett-Packard 10529A Logic omparator,
u ed to verify correct I operation. This device
lip onto in-circuit I ' and in tandy di pla y
any logic tate differen ,between the incircuit
test I and the reference I in the comparator.
Hew lett-Packard 10526T Logic Pulser, used to
stimulate in -circuit I ' 0 that the arc driven
to their opposite tate.
Textroni 465
cilloscope, previou sly men -
tioned. for viewing wavelength s.
C.A . ROBI NSON'S Jim Tomei uses a probe to determine
the condition of a logic board's chips. Tomei took
electronics in high school and additional courses during hi s
Army duty. After being discharged from the Army, he first
worked as a tv repairman in Chatsworth. I n addition to the
standard technician's tools, Tomei recommends including a
jeweler's screwdriver with a narrow or flat tip for prying
out pins in logic connectors.
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