Lincoln Electric SVM123-A service manual Toc

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F-54 TROUBLESHOOTING & REPAIR F-54

SCR OUTPUT BRIDGE REPLACEMENT

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7.Using a 3/8” socket wrench, attach the two screws (one on each side) holding the SCR assembly rails to the front panel assembly. See Figure F-23.

NOTE: It may have been necessary to move or remove the output choke to gain access to the bottom anode leads. For access to the bottom middle screw, nut, and associated washers, a long handled flat ratchet is recommended.

8.Using a 1/2” socket and open-end wrench, attach the secondary leads that connect the anodes of the SCR heat sink assemblies to the six transformer secondary (heavy alu- minum) leads as labeled during dis- assembly.

9.Using a 5/16” socket attach the small reed switch lead (#210) to the left, top rear SCR heat sink using the screw previously removed.

10.Using a 9/16” socket and open-end wrench, attach the two bolts and nuts holding the shunt assembly to the two positive buss leads con- nected to the SCR bridge.

11.Feed the J4 gate lead Molex plug up through the hole in bottom of the PC board compartment. Attach the plug onto the firing board.

12.Secure any cable ties removed pre- viously to allow for the SCR bridge assembly removal.

13.Using a 5/16 (8mm) nut driver or flat head screw driver, attach 20 screws (ten per side) to attach the case sides. Attach the top using 2 similar screws.

14.Raise the front control panel into position, and, using a 5/16 (8mm) nut driver or flat head screw driver, secure in position using 6 screws.

IDEALARC DC-1000