Lincoln Electric DC-655 IM602-A Operator's Manual page 35

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PC BOARD TROUBLESHOOTING GUIDE -
1. All 10 LED's must be ON when the POWER SOURCE is turned ON and the wire feeder's trigger is closed, or
a jumper is placed between 2 & 4, or the "OUTPUT TERMINALS SWITCH" is in the ON position.
2. LED's 7, 8, and 9 indicate AC power being supplied to the P.C. board from auxiliary windings (T1). If a light is
not on, turn the machine off and unplug P5 from the firing board. Turn the machine back on and check the fol-
lowing voltages:
Light that was off
7
8
9
3. If all voltages are present, turn power off, and plug P5 back into J5. Turn power back on. If LED's are still out,
replace firing PCB.
4. If voltages were not present then check the wiring back to the auxiliary windings for a possible open.
5. LED's 1 through 6 indicate gate signals are being sent to the main SCR's 1 through 6 respectively If LED5 is
on (CONTROL BOARD), along with LED7, 8, and 9 on firing PCB, and LED's 1 through 6 are not on, check to
make sure lead 231 between control board and firing board is not broken.
6. If any one of LED 1 through 6 are not on and LED's 7,8, and 9 are on, replace the firing PCB.
PC BOARD TROUBLESHOOTING GUIDE -
1. LED1 indicates that the CC mode switch is closed. When the CC mode switch closed LED6 should also illu-
minate. See LED6.
2. LED2 indicates that there is feedback voltage present in CV mode.
3. LED3 indicate an input shutdown. Refer to
4. LED4 indicates an over current fault shutdown. Refer to
Operation Section.
5. LED5 Indicates Output Current should be present.
6. LED6 indicates that the machine is in CC mode. This LED should light whenever LED1 lights. If not the
Control PC Board may be faulty.
7. LED7 +16V power supply
8. LED8 indicates the Control PC Board is signalling the Firing PC Board to fire the SCRs.
9. LED9 -10V power supply
10. LED10 indicates that 42V input is present to the Control PC Board
11. LED11 indicates that there is feedback voltage present in CC mode.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
Check AC voltage between
P5 pins 15 & 16 (wires 230,204)
P5 pins 7 & 8 (wires 205,206)
P5 pins 5 & 6 (wires 207,208)
or
FIRING P.C. BOARD
CONTROL P.C. BOARD
in the Operation section.
CAUTION
DC-655
Voltage should be approximately
32VAC
32VAC
32VAC
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and
in the