Mac Repair Central

Logic board

Review the ESD precautions in Bulletins/Safety.

Note: If you are replacing a logic board that has one SIMM slot, replace it with P/N 661-01 58. If you are replacing a logic board that has two SIMM slots, replace it with P/N 661-1114.

Note: The LC 630 DOS-Compatible logic board includes the main logic board with DRAM SIMM, the DOS-Compatible board with DRAM SIMM, DOS-Compatible sound board, DOS-Compatible adapter board, and appropriate cables.

Removing the Adapter Board

1 Disconnect the 26-pin adapter board cable.

2 Gently lift up the battery end of the adapter board and disconnect the board from the PDS slot.

3 Pull the adapter board back and out.

4 Removing the Sound Board

5 Remove the two Phillips screws.

6 Lift the sound board to disconnect and remove it.

Phillips Screw

Phillips Screw

DOS-

Compatible Board

16-pin External Video Out

DOS-

Compatible Board

16-pin External Video Out

Removing the DOS-

Compatible Board

1 Disconnect the 16-pin external video out cable from the logic board.

2 Remove the four Phillips screws from the DOS-compatible board.

Caution: the DOS-compatible board is installed directly into the '040 processor socket. Use extreme caution not to bend the processor pins when you remove the DOS-compatible board from the main logic board.

3 Gently loosen each side of the DOS-compatible board from the processor socket.

4 Lift off the board.

Replacement Note: Return a defective DOS-Compatible board to Apple service with the 68LC040 processor installed.

68LC040 Processor Socket

Main Logic Board

68LC040 Processor Socket

Main Logic Board

DRAM SIMM

Standoff Nuts (Un Solder Side)

DRAM SIMM

Standoff Nuts (Un Solder Side)

Note: To return the main logic board to Apple, remove the DRAM SIMM, the standoffs, sound, adapter and DOS- compatible boards. In addition, transfer the 68LC040 processor from the DOS-compatible board to the main logic board processor socket. Procedures for removing and installing the 68LC040 processor follow.

Removing the Standoffs from the Main Logic Board

Remove the four standoff nuts from the solder side of the main logic board and lift off the standoffs.

DOS-Compatible Board

Processor Removal Tool

Processor Removal Tool

68LC040 Processor

Removing the 68LC040 from the DOS-Compatible Board

Caution: The 68LC040 processor pins are fragile. To avoid bending the pins, gently loosen the pins from each side of the processor and lift the processor straight up. To avoid scratching the tracings on the logic board, avoid contacting the logic board with the processor removal tool

1 Using the processor removal tool, gently pry up all four sides of the 680LC40 processor from the DOS-compatible board.

2 Lift the processor straight up and remove it.

Logic Board

Logic Board

Anti-static Foam

Installing the 68LC040 processor in the main logic board socket.

Caution: The following procedure protects the EMI clips and avoids warping the logic board and thus harming the tracings.

1 Support the processor socket area of the main logic board with several thicknesses of antistatic foam.

Processor Alignment Corner—

Processor Alignment Corner—

iiiiri

Socket Alignment Corner iiiiri

Note: A missing pin and pin socket hole mark the alignment corners of the 68LC040 processor and socket.

2 Locate the alignment corners of the 68LC040 processor and the processor socket.

Socket Alignment Corner

Processor Alignment Corner

Socket

Alignment

Corner

Processor Alignment Corner

Socket

Alignment

Corner

Caution: Avoid bending the processor pins when you install the 68LC040 processor. If you meet resistance, realign the pins and standoffs.

3 Carefully position the processor alignment corner over the socket alignment corner.

4 Press the pins firmly into the socket.

Rear Panel

Rear Panel