
Section TOC
Master TOC
|
| TROUBLESHOOTING & REPAIR |
CHOPPER PC BOARD REMOVAL AND REPLACEMENT (CONTINUED)
Return to
Return to Section TOC
Return to Section TOC
Return to Section TOC
Return to
Return to Master TOC
Return to Master TOC
Return to Master TOC
3.Perform the Case Cover Removal proce- dure.
4.Perform the Power Capacitor Discharge procedure.
5.Carefully turn the machine onto its side.
6.Using the 3/8" wrench, remove the four screws holding the tunnel assembly to the machine base. Support the tunnel assem- bly, then carefully turn the machine back upright.
7.With the slot head screw driver, carefully raise the tunnel assembly unit about one inch and block it with the piece of wood. This will allow access to the bottom allen head screws on the Chopper PC Board. Peel away the
8.Disconnect the plug harness connection above the Chopper PC Board. Slip the wires out of the cord clip.
9.Using the 7/16" wrench, loosen the bolt at the positive capacitor terminal. Then remove the two nuts, lock washers and flat washers holding the positive strap to the Chopper PC Board. Hold the screw heads behind the board with your finger to remove the nuts. Note the placement of the reverse diode lead on the bottom bolt. Note the fastener order for reassembly: flat washer, lock washer, nut.
10.With the 7/16" wrench, remove the two
11.Using the 3/16" allen head wrench, remove the two
12.Swing the positive capacitor strap out of the way and remove the Chopper PC Board.
REPLACEMENT
Refer to Figure F.14.
1.Make sure the mating surfaces between the copper and the heat sink are clean, dry, and free of grease.
2.Apply a thin coating of electrical thermal joint compound (Penetrox
3.Using the torque wrench and 3/16" allen head socket, install the two
4.Using the 7/16" socket and torque wrench, install the two bolts, lock washers, and flat washers that hold the Chopper PC Board to the heat sink. Note the two spacers required. Tighten the bolts finger tight, then to between 50 and 60
5.Put the positive strap (+) in position and the proper heavy lead. Using the 7/16" wrench, tighten the bolt at the positive capacitor ter- minal to between 50 and 60
6.Remove the wooden blocking and carefully lower the tunnel assembly onto the machine base. Support the tunnel assem- bly and turn the machine onto its side.
7.With the 3/8" wrench, install the four screws that hold the tunnel assembly to the machine base. Turn the machine back upright.
8.Connect the harness plug above the Chopper PC board. Slip the wires into the cord clip.
See the procedures following for removal and replacement of the diode module. When proce- dures are complete, perform the Case Cover Assembly Replacement procedure.