Esistance checks per table f.4, Troubleshooting & repair, Output power board resistance test (continued) – Lincoln Electric PRO-CUT 55 SVM140-A User Manual
Page 63
6. If any of the resistance checks are not correct, the
output power board is faulty. Replace. See the
Output Power Board Removal and Replacement
Procedure. Note: Use D30 test point for boards
G3326-2,3.
7. If the output power board “passes” the resistance
test, the power diode and transistor portion of the
board is good. However, other circuits on the
power board may be faulty. These circuits are NOT
readily tested or serviceable.
8.
Reconnect the leads and plugs previously
removed.
TROUBLESHOOTING & REPAIR
F-26
F-26
PRO-CUT 55
TABLE F.4 - OUTPUT POWER BOARD RESISTANCE
CIRCUIT OR
TEST POINTS
COMPONENT(S)
EXPECTED RESISTANCE
BEING TESTED
+Probe J33-Pin4
Diode A1
Less than
to
and
100 ohms
–Probe Terminal B11
associated trace
+Probe Terminal B11
Diode A1
Greater than
to
and
1000 ohms
–Probe J33-Pin4
associated trace
+Probe J33-Pin4
Diode A1
Less than
to
and
100 ohms
–Probe Terminal B12
associated trace
+Probe Terminal B12
Diode A1
Greater than
to
and
1000 ohms
–Probe J33-Pin4
associated trace
or D30
+Probe R5 Test Point
Diode A2
Less than
to
and
100 ohms
–Probe Terminal B1
associated trace
+Probe Terminal B1
Diode A2
Greater than
to
and
1000 ohms
–Probe R5 Test Point
associated trace
or
–Probe D30 Test Point
or D30
+Probe R5 Test Point
Diode A2
Less than
to
and
100 ohms
-Probe Terminal B2
associated trace
+Probe Terminal B2
Diode A2
Greater than
to
and
1000 ohms
–Probe R5 Test Point
associated trace
or
–Probe D30 Test Point
+Probe R5 Test Point
Transistor A2
Less than
to
and
100 ohms
–Probe J32-Pin14
associated trace
+Probe J32-Pin14
Transistor A2
Greater than
to
and
1000 ohms
–Probe R5 Test Point
associated trace
or
–Probe D30 Test Point
OUTPUT POWER BOARD RESISTANCE TEST (continued)