Lincoln Electric IDEALARC DC-655 Service Manual page 57

F-15
POSITIVE
OUTPUT
TERMINAL
TERMINAL STRIP
COVER PANEL
+21 -21 41 4 2
TERMINAL STRIP
4. Check for the presence of 42 VAC at the ter-
minal strip ( #2 to #41). See the Simplified
Trigger Diagram.
5. If 42 VAC is not present at the terminal strip,
check the circuit breaker and leads #42A
and #41 at the P15 connector.
Simplified Trigger Diagram. Also perform
the Main Transformer Test.
6. Remove the main input supply power to the
DC-655 machine.
7. Check continuity (zero ohms) from lead
#42A ( plug P15 pin-13) to lead #2 at the 14-
pin receptacle pin "C". Also check continu-
ity to the output terminal switch. See the
Simplified Trigger Diagram. If a resistance
of any value is indicated, check the associ-
ated wires and plugs.
TROUBLESHOOTING & REPAIR
FIGURE F.2 – TERMINAL STRIP AND 14-PIN RECEPTACLE
14 PIN MS RECEPTACLE
LOW INDUCTANCE
NEGATIVE OUTPUT
TERMINAL
31 32 75 76 77
IDEALARC DC-655
B=GND
L
C=2
D=4
E=77
HIGH INDUCTANCE
NEGATIVE OUTPUT
TERMINAL
8. Check continuity (zero ohms) from pin "D"
(lead #4) at the 14-pin receptacle to the out-
put terminal switch and also to plug J5-pin
9 at the firing board. See the Simplified
Trigger Diagram and Figures F.1 and F.2. If
a resistance of any value is indicated, check
See the
the associated wires and plugs.
K=42
A=32 J=31
I=41
F=76
M
F-15
N
H=21
G=75