Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B Service Manual page 137

F-77
SNUBBER AND BLEEDER RESISTOR TEST (continued)
TEST PROCEDURE
1. Remove main input supply power to the
machine.
2. With the 3/8" nut driver, remove the 4
screws that hold the handle to the machine.
3. Remove the rubber gasket (cover seal) from
the lift bail.
4. With the 5/16" nut driver, remove the sheet
metal screws from the case top.
5. With the 5/16" nut driver, remove the
screws holding the right and left case sides.
Remove the case sides by lifting up and
out.
6. Perform the Capacitor Discharge Proce-
dure described earlier in this section of the
manual.
WARNING
Before continuing with the
test procedure, perform the
capacitor discharge proce-
dure to avoid electric shock.
7. Perform the following tests on the four
switch boards:
Switch Board 1: (Switch Board 1 is Marked
CAP 1 on the Switch Board Assembly
Connection Decal - See Figure F.24.)
A. Remove quick connect terminals #401,
#402, #9, and #12 from switch board 1.
B. With the volt/ohmmeter, check for 25
ohms resistance between lead #401 and
#12E.
If the measurement reads between 20 and
30 ohms, resistor R1 and leads #401 and
#12E are okay. Go to step C.
If the measurement does not read between
20 and 30 ohms, check for continuity in
leads #401 and #12E. Then test for 25
ohms resistance across R1 directly. If the
measurement does not read between 20
and 30 ohms, replace resistor R1.
TROUBLESHOOTING & REPAIR
POWER WAVE 450
C. With the volt/ohmmeter, check for 25
ohms resistance between lead #402 and
#9E.
If the measurement reads between 20 and
30 ohms, resistor R2 and leads #402 and
#9E are okay. Go to step D.
If the measurement does not read between
20 and 30 ohms, check for continuity in
leads #402 and #9E.
ohms resistance across R2 directly. If the
measurement does not read between 20
and 30 ohms, replace resistor R2.
D. With the volt/ohmmeter, check for 7.5 K-
ohms resistance between lead #12L (12E)
and #9L (9E).
If the measurement reads between 6.75
and 8.25 K-ohms, resistor R9 and leads
#12L(12E) and #9L (9E) are okay. Go to
step E.
If the measurement does not read between
6.75 and 30 K-ohms, check for continuity
in leads #12L (12E) and #9L(9E). Then test
for 7.5 K-ohms resistance across R9
directly. If the measurement does not read
between 6.75 and 8.25 K-ohms, replace
resistor R9.
E. Reconnect quick connect terminals #401,
#402, #9, and #12 on switch board 1.
Switch Board 2: (Switch Board 2 is Marked
CAP 2 on the Switch Board Assembly
Connection Decal - See Figure F.24.)
A. Remove quick connect terminals #403,
#404, #9, and #12.
B. With the volt/ohmmeter, check for 25
ohms resistance between lead #403 and
#12F.
If the measurement reads between 20 and
30 ohms, resistor R3 and leads #403 and
#12F are okay. Go to step C.
If the measurement does not read between
20 and 30 ohms, check for continuity in
leads #403 and #12F. Then test for 25
ohms resistance across R3 directly. If the
measurement does not read between 20
and 30 ohms, replace resistor R3.
F-77
Then test for 25