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TROUBLESHOOTING & REPAIR |
POLARITY SWITCH
REMOVAL AND REPLACEMENT PROCEDURE (Continued)
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REMOVAL PROCEDURE
1.Remove the input power to the TIG 185 machine.
2.Using the 3/8” nutdriver remove the case
3.Using the 3/32” Allen type wrench remove the output control knob.
4.Using the Phillips head screwdriver remove the screw from the polarity switch handle.
5.With the 2 slot head screwdrivers carefully pry the polarity switch han- dle from the shaft.
6.Remove the five plastic snap rivets holding the name plate to the case front. These can be removed by gen- tly prying at the rivet between the name plate and the case front.
7.Remove the name plate.
8.With the 1/2” wrench remove the “positive” flex lead from the polarity switch. See wiring diagram. Label lead and connection point for reassembly.
9.With the 1/2” wrench remove the “AC” flex lead from the polarity switch. This lead connects to the AC plate on the SCR bridge. See wiring diagram. Label lead and connection point for reassembly.
10.Using the 1/2” wrench remove the flex lead from the rear gang of the polarity switch. This lead connects to the D1 diode on the SCR bridge. See wiring diagram. Label lead and connection point for reassembly.
11.Using the 1/2” wrench remove the flat copper lead from the polarity switch. This lead connects to the high frequency transformer coil and the
tion point for reassembly.
12.Using the 1/2” wrench remove the other flat copper lead from the polarity switch. This lead connects to the lower terminal on the
13.Using the 1/2” wrench remove the choke lead from the polarity switch. See wiring diagram. Label lead and connection point for reassembly.
14.With the 1/2” wrench remove the X1 secondary lead from the polarity switch. See wiring diagram. Label lead and connection point for reassembly.
15.With the 7/16” wrench remove the two nuts and washers that hold the polarity switch to the front panel.
16.Carefully rotate the polarity switch assembly to gain access to the
17.Carefully unsolder the two leads (#311 and #312) from the micro- switch located on the polarity switch assembly. See wiring diagram. Label leads and connection points for reassembly.
18.Carefully remove the polarity switch assembly from the machine.
