Troubleshooting And Repair - Lincoln Electric SVM154-A Service Manual

F-30
TEST PROCEDURE
1. Remove input power to the LN-10 unit.
2. Using the 5/16 in. nut driver, remove
the wire drive cover.
3. Locate the gas solenoid and lead con-
nection. See Figure F.5. Do not discon-
nect the leads.
4. Apply the correct input power (42 VAC)
to the LN-10 unit.
5. While pressing the gas purge button or
activating the gun trigger, check for
approximately 10 VDC at the solenoid
leads. If the 10 VDC is present the gas
solenoid should activate.

TROUBLESHOOTING AND REPAIR

GAS SOLENOID TEST (continued)
FIGURE F.5 — GAS SOLENOID TEST.
GAS SOLENOID
LEAD
NOTE: WIRE FEEDER SHOWN
WITH DRIVE MOTOR ASSEMBLY
REMOVED FOR CLARITY
SOLENOID
6. If the 10 VDC is missing or low, check
the leads and connections between the
solenoid and the control board. See the
Wiring Diagram. If the leads and con-
nections are OK the control board may
be faulty.
7. If the 10 VDC is present at the solenoid
leads and the solenoid does not
activate the solenoid may be faulty.
Normal solenoid coil resistance is
approximately 22 ohms.
8. The solenoid can be further checked by
disconnecting the solenoid leads from
the LN-10 wiring harness and applying
an external 12 VDC supply to the leads.
If the solenoid does not activate the
solenoid is faulty.
9. Reconnect all disconnected leads.
10. Install the wire drive cover.
LN-10
GAS
F-30