Macintosh SE/30 General Maintenance
Cleaning, the PRAM battery, the logic board capacitors, connectors, rail checks and adjustments for the Macintosh SE/30.
The SE/30 contains a CRT. Read CRT Discharge Procedure before opening the case. Apple's instruction is to discharge the CRT to the ground lug before disconnecting anything, and not to put on a grounding wriststrap until the CRT has been discharged.[1] Apple's hardware guide warns that the tube and video circuits may hold dangerous charges long after the power is off.[2]
Logic board capacitors
[edit | edit source]The SE/30 logic board has surface-mount aluminium electrolytic capacitors, and they leak. Recap-a-Mac's advice is that every SE/30 has leaky capacitors and that an unrecapped board should be done before the damage spreads.[3] The electrolyte creeps under nearby chips and along traces, and the corrosion is what kills the board.
- Replace all the electrolytics as a set; values and positions are on Macintosh SE/30 Capacitor Replacement Guide.
- Clean the board afterwards. Electrolyte left in place keeps corroding.
- Check continuity on the traces under and beside each capacitor before deciding the board is dead. Broken traces can be repaired with wire.
- Recap a machine that has been in storage before powering it up.
Recap-a-Mac sees the damage most often in the video multiplexers (the row of Ux8 chips below the large axial capacitor) and the F258 RAM multiplexers above the ROM slot.[3]
Where things are on the logic board
[edit | edit source]Designators from the pin-matrix sheets and the VIA/RTC/ADB sheet of the macse30mlb redraw of Apple drawing 050-0253-01:[4]
| Designator | Device |
|---|---|
| UK8 | 68030 CPU |
| UI5 | 68882 FPU |
| UI8 | GLUE |
| UK12, UK11 | VIA1, VIA2 |
| UK4 | Real-time clock, with 32.768 kHz crystal Y1 |
| UL11 | ADB controller |
| UJ11 | SWIM floppy controller |
| UI12 | SCSI controller |
| UG12 | 8530 serial controller |
| UE10 | Sound chip (Apple Sound Chip) |
| UK6 | Video ROM |
| UC6, UC7 | Video RAM |
| UA8, UB8, UC8, UD8 | Video multiplexers |
| UI2, UI3, UI4, UJ2, UJ3, UJ4 | RAM address multiplexers |
| S1A–S4A, S1B–S4B | RAM SIMM sockets, banks A and B |
| J12 | Power and video connector from the analogue board |
| J13 | 030 direct slot (PDS) |
| F1 | 1 A fuse in the +5 V feed to the two ADB ports |
If the keyboard and mouse are both dead, check F1 before the ADB chip: it feeds +5 V to both ports.[4]
PRAM battery
[edit | edit source]The SE/30 keeps 256 bytes of parameter memory in a CMOS custom chip, backed by a long-life lithium cell in a holder.[1] Pina gives it as a 3.6 V half-AA snap-in cell;[5] the schematic redraw labels BT1 "3.0V, 1/2AA".[4] A machine that will not keep the time and date needs a new cell (Pina, p. 180).[5]
Apple's test: remove the logic board, set the meter to its 10 V DC range, and replace the cell if it reads below 2.8 V. To replace it, remove the cover from the battery holder, pull the cell out, and fit the new one with its "+" end matching the "+" on the board.[1]
The cell is lithium. Neutralise leakage with a bicarbonate of soda solution, not vinegar, then isopropyl alcohol, with ventilation. Leakage from the cell lands on the same area as the capacitor leakage, so inspect the whole board. See Battery Explosion, Capacitor or Corrosion Damage and Battery Refurbishment.
Cleaning
[edit | edit source]- Unplug the machine and discharge the CRT before working inside.
- Remove dust from the analogue board, logic board and fan with a soft brush or compressed air.
- Clean boards with isopropyl alcohol (90 % or stronger) and a soft brush; this is also the clean-up after a recap.
- Clean the case with a damp cloth and mild soap. For a yellowed case see Retrobrite.
Connectors and the ROM SIMM
[edit | edit source]Reseat and clean the analogue board cable at J12, the floppy and SCSI cables, the yoke cable and video board, the speaker and fan leads, any PDS card, and the ROM SIMM. Pina's fixes for a Sad Mac with 00000001 over any value (p. 181) and for a checkerboard with no startup sound (p. 175) are both to reseat the ROM SIMM.[5] See Sad Mac Error Codes and the Sad Mac Decoder.
If the display blinks out or white lines flash across it, and tapping the cabinet brings the fault back, Pina finds the CRT socket board loose on the neck of the tube and secures it with a dab of hot glue (p. 158).[5]
Analogue board and power supply
[edit | edit source]The SE/30 has the SE's analogue board (661-0371), power supply (661-0370) and video board (982-0024).[1] Their faults are the SE's: see Macintosh SE General Maintenance#What fails and Macintosh SE Troubleshooting#Analogue board faults. When fitting a replacement axial fan, Apple requires the later, vertically mounted video board; the axial fan does not leave enough vibration clearance for the old horizontal board.[1]
Rail checks
[edit | edit source]| Rail | Limits | Logic board connector J12 |
|---|---|---|
| +5 V | 4.85–5.20 V | pins 12, 13 |
| +12 V | 11.50–12.50 V (sweep); 11.50–12.80 V (disk) | pin 14 |
| −12 V | −13.20 to −10.80 V | pin 7 |
| −5 V | regulated on the analogue board | pin 6 |
| Ground | pins 1–5, 8 |
Pins 9, 10 and 11 of J12 carry video, horizontal sync and vertical sync.[6] Ripple limits are 20 mV (line frequency) and 40 mV (switching) peak-to-peak on +5 V, and 30 mV and 50 mV on the 12 V outputs.[6] There is no voltage adjustment on the SE/30; Apple's Adjustments chapter covers the yoke and the video only.[1] The R56 trimmer in Apple's Macintosh Plus procedure is the single voltage-adjust control of the 128K/512K/Plus power/sweep board, where it moves +5 V and +12 V together; the SE/30 does not have that board.
Adjustments
[edit | edit source]Apple's video adjustments for the SE/30, made from the rear with a mirror:[1]
- Brightness. Turn the external contrast fully clockwise. Turn the brightness control on the analogue board anticlockwise until white lines show, then clockwise until they just disappear, then slightly anticlockwise.
- Size. With a plastic hex tool, set the raster 7 inches wide and 4.7 inches high.
- Focus. Turn the focus control fully clockwise, then back one-eighth of a turn.
- Yoke. Loosen the yoke clamp two or three turns, switch on, and rotate the collar until the picture is square to the bezel; switch off, unplug and discharge the CRT before tightening. Centre the picture with the two rings.
Related pages
[edit | edit source]- Macintosh SE/30
- Macintosh SE/30 Capacitor Replacement Guide
- Macintosh SE/30 Memory Upgrade Guide
- Macintosh SE/30 Troubleshooting
- Macintosh SE/30 Logic Board Schematic
- Macintosh SE/30 Reloaded Logic Board
- CRT Discharge Procedure
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Apple Computer, Macintosh SE/30 Service Source (89 pp.), hosted here as File:Macintosh SE30.pdf (see Macintosh SE/30 Service Source). Take Apart PDF pp. 28–68; Additional Procedures, Battery Verification and Replacement, PDF pp. 70–74; Adjustments PDF pp. 76–87; Exploded View PDF p. 89.
- ↑ Apple Computer, Guide to the Macintosh Family Hardware, 2nd edition, Addison-Wesley, 1990, Chapter 5, p. 209. Hosted here: File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf.
- ↑ 3.0 3.1 Macintosh SE/30, Recap-a-Mac—link(accessed 2026-09-30)
- ↑ 4.0 4.1 4.2 Macintosh SE/30 Main Logic Board Schematic Drawings, macse30mlb project, KiCad recreation of Apple engineering drawing 050-0253-01, MIT licence (https://github.com/mishimasensei/macse30mlb). Address- and data-line pin matrices; "VIA1, VIA2, RTC, Apple Desktop Bus" sheet. Hosted here: File:Macintosh SE30 Logic Board Schematic Redraw 050-0253-01.pdf (see Macintosh SE/30 Logic Board Schematic).
- ↑ 5.0 5.1 5.2 5.3 Larry Pina, The Dead Mac Scrolls, Peachpit Press, 1992, chapter 2 "Mac SE and SE/30" (book and PDF page numbers are the same). Hosted here: File:The Dead Mac Scrolls 1992.pdf (see The Dead Mac Scrolls).
- ↑ 6.0 6.1 6.2 Apple Computer, Guide to the Macintosh Family Hardware, 2nd edition, 1990, Chapter 6: Table 6-2, p. 247; Table 6-3, p. 248; Table 6-15, p. 259; Table 6-17, p. 260.