Troubleshooting & repair – Lincoln Electric VANTAGE 400 User Manual
Page 118
WELD CONTROL BOARD PWM GATE SIGNAL TEST (CONTINUED)
TEST PROCEDURE
1. Perform the Case Cover Removal
2. Unplug any device that may be attached to
either the 6 pin or the 14 pin Amphenol recep-
tacles.
3. Place the idle switch in the “HIGH IDLE” posi-
tion.
4. Place the mode switch in the “CC-STICK”
position.
5. Place the Weld terminals switch in the “WELD
TERMINALS ON” position.
6. Start the engine and let it run and stabilize at
high idle RPM.
7. Locate plug P3 on the control PC board. See
Control Inner-Connection diagram.
8. Use the frequency counter to test for 20kHz
PWM gate signal between leads #23+ (P3-10)
and #25- (P3-9).
9. If the 20KHz gate signal is present, place the
weld terminals switch in the ”REMOTELY
CONTROLLED” position. The gate signal
should turn off.
10. If the 20 KHz gate signal responds as
described above, this test is complete.
11. If there is no 20 KHz gate signal, test for the
presents of 80 to 100 VDC, at leads 13+ (P3-
8) to 14- (P3-16) of the weld control PC
board.
12. If voltage is very low or not present, check
leads #13 and #14 for faulty or damaged
wiring or connections between the control PC
board and the chopper module.
13. Test for 80 to 100 VDC at the terminals where
the #13 and #14 leads connect to the chopper
module. See the wiring diagram. If there is
no voltage at the chopper module, perform
the chopper module function test.
14. If the 80 to 100 VDC supply voltage is present
at the weld control PC board, but there is no
PWM gate signal, check the voltage between
leads #2+ (P1-4) and #4 (P1-3). See figure
#1
The voltage should be about 0 VDC.
15. If about 5 VDC is detected, the welding termi-
nal control circuit is open. Check for dam-
aged leads for faulty connections at leads #2
and #4; also check for a defective welding ter-
minal switch. See the wiring diagram.
16. If the PWM signal remains after the welding
terminal switch has been placed in the
“REMOTELY CONTROLLED” position, check
the voltage between leads #2+ (P1-4) and #4-
(P1-3) at the control PC board.
17. If the voltage reads 0 or very near 0, Check
for damaged insulation at leads #2 and #4,
also check for a shorted welding terminal
switch, or damaged or contaminated
Amphenol receptacle. See the wiring dia-
gram.
18. If the above wiring and components are
undamaged and functioning properly, the con-
trol PC board is defective and should be
replaced.
19. If the voltage reads about 5 VDC, and the
PWM signal remains, the control PC board is
defective and should be replaced.
20. Perform the Case Cover Replacement
TROUBLESHOOTING & REPAIR
F-70
F-70
VANTAGE® 400