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F-43 TROUBLESHOOTING & REPAIRF-43
SCR BRIDGE ASSEMBLY
REMOVAL AND REPLACEMENT PROCEDURE (Continued)
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16.With the 3/8” wrench remove the four mounting screws holding the SCR bridge assembly to the main transformer frame. Note insulator placement.
17.Carefully remove the SCR bridge assembly from the TIG 185 cutting any necessary cable ties.
REPLACEMENT PROCEDURE
1.Carefully place the new SCR bridge assembly in position in the TIG 185.
2.Using the 3/8” wrench install the four mounting screws taking special care that the insulators are in the correct positions.
USE DOW CORNING 340 HEAT SINK COMPOUND ON ALL ALUMINUM CONNECTIONS
3.Assemble the positive lead to the right side positive heat sink.
4.Assemble the lead from the polarity switch to the right side AC heat sink. Note: Also connect lead #216
5.Assemble the shunt to the SCR bridge left side negative heat sink.
6.Assemble the X2 secondary trans- former lead to the left side AC SCR heat sink. Note: Also connect lead #217
7.Assemble the diode pigtail lead to the polarity switch lead. See Figure F.10. Be sure to replace sleeving and secure with cable ties. Position with harness and secure with cable ties.
8.Replace any previously removed cable ties.
9.Position the internal divider panel and secure with the screws previous- ly removed.
10.Install the J2 plug into the control board and position the harness in the internal divider panel.
11.Position and install the case back and secure with the screws previ- ously removed.
12.Install the gas hose onto the sole- noid valve.
13.Tighten the input cable strain relief.
14.Assemble the case