Lincoln Electric IDEALARC DC-1500 Service Manual page 88

F-54
SCR OUTPUT BRIDGE REPLACEMENT (continued)
Removal Procedure:
1. Remove the input power from the DC-1500.
2. Remove the roof and all case sides.
3. Use a static strap when working with the con-
trol and firing p.c. boards.
molex plugs from the two p.c. boards.
Disconnect leads #74 and the ground lead
from the control p.c. board.
4. Disconnect lead #31A from the 5CR relay.
5. Remove screws that mount relays 5CR and
2CR.
6. Disconnect the ground lead from the enclo-
sure.
7. Remove the firing p.c. board (bottom) and set
aside.
8. Remove the two screws that mount the p.c.
board enclosure to the front (-4) rectifier. Set
these two smaller mounting screws aside for
use later.
9. Remove the two screws that mount the enclo-
sure to the horizontal panel.
10. Carefully remove the enclosure.
11. Disconnect the copper connection that's
behind the enclosure. Note that this connection
also has three flex leads attached.
12. On the other side of the unit remove the (4)
bolts that connect the L-shaped copper leads
to the rectifier copper straps.
13. Cut cables ties from at terminal strips G1,G2
and G6.
14. Un-plug both snubber p.c. boards.
15. Disconnect leads G5 and G6 from rectifier #6
(left - viewed from rear).
16. Disconnect flex lead #240 from the top alu-
minum lead on rectifier #6. Disconnect flex
lead #243 from the bottom aluminum lead on
rectifier #6.
TROUBLESHOOTING AND REPAIR
Disconnect all
IDEALARC® DC-1500
17. Disconnect leads #211 and #247 from the bot-
tom thermostat on rectifier #6.
18. Disconnect the top aluminum lead on rectifier
#6. Disconnect the bottom aluminum lead on
rectifier #6.
19. Remove the (4) screws that mount rectifier #6.
20. Remove the top fiber air baffle.
21. Carefully remove rectifier #6 from the unit.
22. Disconnect flex lead #241 from the top alu-
minum lead on rectifier #5. Disconnect
lead #244 from the bottom aluminum lead on
rectifier #5.
23. Disconnect flex lead #242 from the top alu-
minum secondary lead on rectifier #4.
Disconnect flex lead #245 from the bottom alu-
minum secondary lead on rectifier #4.
24. Disconnect leads G1 and G2 from rectifier #4.
25. Disconnect leads #212 and #247 from the top
thermostat on rectifier #4.
26. Disconnect leads G3 and G4 from rectifier #5.
27. Disconnect the top aluminum secondary lead
on rectifier #4. Disconnect the bottom alu-
minum secondary lead on rectifier #4.
28. Remove the (4) screws that mount rectifier #4.
29. Carefully remove rectifier #4 from the unit.
30. Disconnect the top aluminum secondary lead
on rectifier #5. Disconnect the bottom alu-
minum secondary lead on rectifier #5.
31. Remove the (4) screws that mount rectifier #5.
32. Carefully remove rectifier #5 from the unit.
F-54
flex