File:Apple Technical Procedures Macintosh and Macintosh Plus 1987.pdf

Apple's Apple Technical Procedures: Macintosh and Macintosh Plus, the dealer service manual for the original Macintosh (128K and 512K) and the Macintosh Plus, pages marked rev. Feb 87 to rev. Jun 87 (108 PDF pages, scanned). Sections: 1 Basics (safety, CRT disposal, keyboard identification, Macintosh and Macintosh Plus differences, theory of operation); 2 Take-Apart (cover, anode discharge, power/sweep board, logic board, CRT, internal drive, keyboard); 3 Diagnostics (MacTest and its error codes); 4 Troubleshooting (symptom chart); 5 Adjustments (power/sweep voltage adjustment, yoke, video); 6 Additional Procedures (Macintosh Plus disk drive and logic board kits, 800K drive exchange and ejection problems, logic board ROM upgrade and 400K drives, alternate chassis screw sizes, removing the CRT overspray, ROM version compatibility); 7 Illustrated Parts. It is module-level: it gives no component values for the power/sweep board. Console5 describes it as excerpted from Apple Technical Procedures Volume 6, part number 072-0062. Described on Apple Technical Procedures: Macintosh and Macintosh Plus.

Its voltage adjustment (p. 5.3) sets +12 V to 12.3 V within 11.90-12.3 V and +5 V within 4.85-5.15 V, measured on the disk drive port with Apple's voltage test cable; the later Macintosh Plus Service Source widens the +12 V window to 11.90-12.75 V.

https://wiki.console5.com/wiki/File:Apple_Technical_Procedures_-_Macintosh_and_Macintosh_Plus.pdf (retrieved 2026-09-30)

Apple Computer, Inc.

Copyright Apple Computer, Inc., 1985, 1986, 1987. Not freely licensed. Hosted for preservation and repair reference.