Logic board 1
Caution Review the ESD precautions in Bulletins Safety. Note The Macintosh Processor Upgrade kit allows 68LC040 computers to switch between a PowerPC 601 processor and a 68LC040 processor. The upgrade board includes the PowerPC 601 processor on board and a socket to accept the customer's 68LC040 processor. Note The PowerPC upgrade for the Macintosh LC 520 and 550 consists of a Macintosh LC 575 logic board, the PowerPC Upgrade Card, a new rear panel, and the 575 product ID label. To install this...
Remove the LC Processor from the Logic Board
1 Locate the 68LC040 processor on the logic board. Position the teeth of the processor removal tool in the groove between the processor and the logic board socket. Caution Be sure to lift up on the handle of the processor removal tool. Pressing down could damage components on the logic board. Note This graphic shows the proper way to remove a 68LC040 chip from its logic board. Your logic board may differ somewhat from this graphic. 3 Caution Pry up each side of the processor only slightly to...
Yoke
Before you begin, remove the rear cover. Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious injury, review CRT safety in Bulletins Safety. Awarning Because you must make yoke adjustments from the rear of the computer, use a mirror to view the computer screen. Do not reach around the computer to adjust collars and rings. Note If you replace the CRT, you will probably need to adjust the yoke. 1 Using an insulated Phillips screwdriver, loosen the yoke...
Front Panel Control Board
1 Disconnect the front panel control cable. 2 Remove the Phillips screw and remove the board. Logic Board Connector and Cable Assembly First remove the EMI shields, speaker assembly, and front panel control board. Overview of removal procedures Detailed steps follow the overview. First disconnect all the connections from the top of the chassis. Then route the cables through to the underside of the chassis and disconnect the logic board connector. Speaker Cable Connector Right Speaker Cable...
Macintosh LC and Manualinject Floppy Drive
Remove the four mounting screws and remove the floppy drive from the carrier. Note Do not remove the metal case from the manual-insert floppy drive in the LC 550 and LC 575. Before you begin, remove the drive bezel. Caution You can access and remove the CD-ROM drive merely by removing the drive bezel at the front of the machine. Although upgrading the CD-ROM drive is now extremely easy, do not neglect to follow proper ESD precautions use a grounded workbench pad, and always wear a grounding...
Cutoff
Note Perform the cutoff and white balance adjustments after the monitor has been on for at least 10 minutes. 1 Use Display Service Utility to display the Gray Bars test pattern. 2 Press the Contrast Up button and set screen contrast to maximum. 3 Select the Screen Control Panel in the Control Panels folder. Drag the Using a hex-head plastic adjustment tool, set the red RB , green GB , and blue BB background controls to the full Set the green GG and blue BG drive controls to their 3 4 position...
Product Information
The LC 575 logic board includes a 68LC040 processor, an additional communications slot, and a new hook-and-loop-attached battery. The LC 520 and LC 550 do not include these features. the newer manual-inject 1.4 MB Apple SuperDrive and require the keyhole-shaped bezel. a revised chassis harness assembly that does not use a floppy drive adapter the newer, caddyless CD 300 CD ROM drive You can exchange the chassis harness assembly of the LC 520 or LC 550 with the newer chassis harness assembly of...
Hard Drive
Before you begin, remove the I O door. Caution You can access and remove the LC 520 hard drive merely by removing the I O door at the rear of the machine. Although upgrading the hard drive is now extremely easy, do not neglect to follow proper ESD precautions use a grounded workbench pad, and always wear a grounding wriststrap. Push down the latch and remove the hard drive. 2 Pull out the hard drive connector adapter.
Identifying the Chassis Harness Assembly
There are three slightly different chassis harness assemblies and Apple service strategy varies with the type of chassis. The three chassis harness assemblies differ according to the combination of floppy and CD-ROM drives they support. Chassis 922-1824 supports the auto-insert Apple SuperDrive and CD-ROM drives earlier than the 300i . This chassis requires a floppy drive adapter, and the CD-ROM connector bridge is about 1-1 2 inches above the CD-ROM drive bay. Chassis 922-0557 supports the...