Filter
Top Products
8-5.
OPTIONAL SPOTIBURNBACK
BOARD
PC2
TESTING
INFORMATION
(Diagram
8-3
And
Figure
8-2)
WARNING: ELECTRIC
SHOCK
can
kill.
A
•
Do
not
touch
live
electrical
parts.
•
Shut
down wire
feeder
and
welding
power
source
or
stop
engine
before
making
or
changing
meter
lead
connections
and
before
disconnecting
or
connecting
any
leads.
MOVING
PARTS
can
cause
serious
Injury.
•
Keep
away
from
moving
parts.
HOT
SURFACES
can
cause
severe
burns.
•
Allow
cooling
period
before servicing.
This
procedure requires the
unit
to
be
ener
-
p
ized.
Only
qualified
persons
familiar
with
and
ollowing
standard
safety practices
are
to
per-
form
this testing
procedure.
A
CAUTION:
ELECTROSTATIC DISCHARGE
(ESD)
can
damage
circuit
boards.
•
Put
on
properly
grounded
wrist
strap
BE-
FORE
handling circuit
boards.
•
Transport
circuit
boards
in
proper
static-
shielding
carriers
or
packages.
•
Perform
work
only
at
a static-safe
work
area.
INCORRECT
INSTALLATION
or misaligned
plugs
can
damage
circuit board.
•
Be
sure
that
plugs
are
properly
installed
and
aligned.
EXCESSIVE
PRESSURE
can
board.
Receptacle
RC4
SA-123
147-E
break
circuit
•
Use
only
minimal
pressure and
gentle
move
-
ment
when disconnecting
or
connecting
board
plugs
and
removing
or
installing
board.
IMPORTANT:
For all checks,
be
sure
to
test
and
verify
the
continuity
of
leads between
the
board
and
the
area
where
check
is
performed.
All
checks
should
go
through
the
connections
and
be
actual
terminal-to-terminal
tests
so
that
bad
connections
or
leads
and
corrosion
are
not
the
problem.
A.
Power
Supply
Circuit
Input
power
of +35
volts dc should
be
present between
pins
A
and
B
(DC
circuit
common)
of
receptacle
RCl.
If
+35
volts dc
are
not
present,
check
that
plug
PLG51
is
secure
in
receptacle
RCl
on
Burnback
Board PC2
and
plug
PLG
1
is
secure
in
receptacle
RCl
on
Motor
Control
Board
PCl.
If
+35
volts dc
are still
not present,
check
Motor
Control
Board
PCl
according
to Section 8-4.
B.
Trigger
Circuit
A
trigger
input
voltage
of +19
volts dc should
be
present
at
pin D
of
receptacle
RCl
with
respect
to
circuit
com
-
mon
when
the
gun
trigger
is
pressed, and
0 volts dc
should
be
present
when
the
gun
trigger
is
released.
If
+19
volts dc
are
not
present
when
the
gun
trigger
is
pressed,
check
Motor
Board
PCi
according
to Section
8-4.
C.
Motor
StartlStop
Circuit
When
the
gun
trigger
is
pressed,
a motor
control
output
voltage
of +24
volts dc
should
be
present
at
pin A
of
re
-
S-2iE
Receptacle
RC3
Figure
8-1.
Motor Control Board
PCi
Component Locations
And
Information
TM-i57i
Page
20