Lincoln Electric INVERTEC V275-S Service Manual page 73

F-43
11. The following checks will verify that the control
board is generating output signals to the
switch board.
12. Apply the correct input power to the V275-S.
13. Check for the presence of approximately
12VDC across the 10K ohm resistor. This is
the voltage generated at the control board to
energize the precharge relay on the switch
board. If this voltage is not present, the con-
trol board may be faulty. See the wiring dia-
gram.
Plug J1
Plug J2
FIGURE F.21 - Plug J2 (on control board)
388
387
TROUBLESHOOTING AND REPAIR
CONTROL BOARD TEST (continued)
FIGURE F.20 - Plug J2 Location
14. Check for the presence of 30KHZ from plug
J10 pin 2 (Lead 308) to pin 6 (Lead 309). This
is the pulse width modulation (PWM) signal
from the control board to the switch board.
See the wiring diagram. If this signal is not
present the control board may be faulty.
15. Remove the above mentioned resistor and
jumper wire.
16. Install plug J10 into the switch board.
17. Replace the case wraparound cover.
Plug J4
FIGURE F.22 - Plug J10 (on main board)
313
307
V275-S
F-43
Plug J3
311
310