Service manual
Model 5304A
Maintenance
SECTION
IX D
5304A TIMER/COUNTER
SUBSECTION
V
MAINTENANCE
9D-5-1. INTRODUCTION
9D-5-2. This section contains maintenance
and
service information
for
Model 5300A/5304A Timer/
Counter. Included
are
performance check procedures
and
tests
to
localize, isolate,
and
locate defective
components.
9D-5-3. RECOMMENDED TEST EQUIPMENT
9D-5-4. Test equipment recommended
for
perform-
ance checks, maintaining, troubleshooting
and
servicing
the
5300A/5304A Timer/Counter
is
listed
in
Table
5-1 of
5300A portion
of the
manual. Test
equipment with equivalent characteristics
may be
substituted
for
equipment listed.
9D-5-5. INSTRUMENT ACCESS
9D-5-6.
For
access
to
plug-on assembly, separate
the
5300A from
the
5304
A as
follows:
a.
Turn
ac
power
OFF and
disconnect power
cord.
b.
Pull
the
two-side casting latches fully rear-
ward
(it is
necessary
to
press
the
latch handles
gently away from
the
center
of the
instrument
to
unlock them).
c.
When latches
are
fully extended rearward,
the
5300A
and
5304A castings should
be
separated
by
cbout '/g-inch.
d.
Lift
the
5300A gently away from
the
5304A.
e.
Separate 5304A
Al
BOARD ASSEMBLY from
5304A casting
as
follows (refer
to
Figure 9D-5-1):
1.
Press rear, plastic-nylon retaining clips
on
each side
of
5304A casting
and
lift
the
rear
of the Al
Board Assembly
to
release
it
from
the
casting.
2.
Press front plastic-nylon retaining clips
on
each side
of
5304A casting
and
lift
the
front
of the Al
Board Assembly
to
release
it
from
the
casting.
3.
Lift
Al
Board Assembly from
the
casting.
f.
Mate
the
5304A,
Al
Board Assembly
to
5300A
and
reapply
ac
power.
g. To
reinstall
the Al
Board Assembly into
the
casting reverse procedure
of
steps
d
through
f.
9D-5-7. PERIODIC MAINTENANCE
9D-5-8.
To
determine
if the
53O0A/53O4A
is
oper-
ating properly within specifications, perform
the In-
Cabinet Performance Checks listed
in
Table 9D-5-1.
These checks
may
also
be
used
for the
5300A
per-
formance checks when
the
5300A/5304A combination
is
used.
9D-5-9. MAINTENANCE
AND
REPAIR
9D-5-10. BOARD REMOVAL. When removing
the
printed circuit board
for
replacement, repair,
or
servicing, always remove
ac
power
and
separate
the
board from
the
casting using Paragraph 9D-5-6
steps
a to e.
9D-5-11. COMPONENT REPLACEMENT. When
replacing
a
circuit board component
use a low
heat
soldering iron. Heat must
be
used sparingly
as
damage
to the
circuit foil
may
result. Mounting
holes
may be
cleaned
out
with
a
toothpick while
heat
is
applied. Connection should
be
cleaned with
a
cleaning solution after component removal
and
replacement.
9D-5-12. INTEGRATED CIRCUIT REPLACEMENT.
Two
methods
are
recommended
for
removing
integrated circuits:
a.
Solder Gobbler. Solder
is
removed from
board
by a
soldering iron with
a
hollow
tip con
nected
to a
vacuum source.
The IC is
removed
intact
so it may be
reinstalled
if
diagnosis
is
wrong.
b.
Clip-Out. This method
is
used when
an IC
is
proven defective. Clip leads close
to
case, apply
heat
and
remove leads with long nose pliers.
Clean board holes with
a
toothpick
and
cleaning
solution.
9D-5-13. INSTRUMENT TROUBLESHOOTING
9D-5-14. Trouble isolation
can
best
be
accom-
plished
by
first obtaining
all
possible information
from
the
controls, connectors,
and
indicators
on the
5300A
and
5304A, then logically using this infor-
mation
to
locate
the
defective component.
If the
9D-5-1