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Replacing electrolytic capacitors (recapping) in your '''Macintosh SE/30''' is essential for restoring power stability, ensuring clean video output, and preventing long-term damage due to capacitor leakage. This guide outlines the recommended procedure and provides complete analog and logic board capacitor specifications.
Every '''Macintosh SE/30''' has leaking capacitors. Not most — all of them. The surface-mount electrolytics on the logic board vent a conductive, corrosive electrolyte that creeps under adjacent ICs and eats traces and vias, and the longer a board is left the greater the chance the damage goes beyond what a recap will fix.<ref name="recapse30" /> This is the single most important fact about the machine, and it is why the logic board comes first on this page and the analogue board second.


== 🔍 Capacitor Inspection ==
== Safety ==


Before recapping, visually inspect all capacitors for common signs of failure:
{{Warning|'''The logic board can be recapped without touching the CRT.''' It lifts out of the chassis once the cover is off. You do not need to discharge the CRT to recap it — but you do need to discharge the CRT before working on the analogue board, the video board, the anode lead or the CRT socket board. See [[CRT Discharge Procedure]].


* '''Bulging Tops''' – Swollen or domed caps indicate internal gas buildup.
'''The power supply is a separate mains-connected module.''' Its primary reservoir is a 620&nbsp;µF 400&nbsp;V capacitor or a series pair of 330&nbsp;µF 200&nbsp;V capacitors depending on which unit is fitted.<ref name="c5se" /> Those sit at rectified mains potential and stay charged after power-off. Measure across them before touching the primary side.
* '''Electrolyte Leakage''' – Brown/white crust or residue near leads shows capacitor failure.
* '''Corroded Pads or Traces''' – PCB staining or corrosion suggests leakage damage.


If any of these symptoms are present, immediate replacement is advised.
'''The lithium battery can explode if mishandled.''' Apple's warning is explicit: "If handled or discarded improperly, the lithium battery in the Macintosh SE/30 could explode."<ref name="APPLESS" />


== 📋 Macintosh SE/30 Capacitor List ==
Apple rates the SE/30 at 120–240&nbsp;V AC, automatically configured, 48–62&nbsp;Hz, 75&nbsp;W maximum.<ref name="APPLESS" />}}


=== 🧯 Analog Board Capacitors ===
== Do the Battery First ==
The SE/30 analog board is nearly identical to that of the Macintosh SE and Plus, and shares the same capacitor layout:
 
Remove or check the 1/2&nbsp;AA lithium PRAM cell before anything else. Apple's procedure is to remove the logic board, measure across the cell on the 10&nbsp;V DC range and '''replace it if it reads below 2.8&nbsp;V'''.<ref name="APPLESS" /> A leaked cell produces exactly the same kind of trace damage as a leaked capacitor, in the same part of the board. See [[Battery Explosion, Capacitor or Corrosion Damage]].
 
== Capacitor Inspection ==
 
On an SE/30 the question is not whether the capacitors have leaked but how far the electrolyte has travelled.
 
* '''Dark haloes or dried crust''' around the base of the surface-mount cans.
* '''Dull, grey or green solder joints''' on nearby IC pins — electrolyte attacks the joint before it attacks the trace.
* '''Missing or thinned traces''' near the capacitors, best seen under a loupe with light across the board.
* Bulging tops are '''not''' a reliable sign on these parts; they usually leak from the base without deforming.
 
See [[Capacitor Failure Symptoms]].
 
== Logic Board ==
 
The SE/30 logic board, Apple part '''820-0260''', carries thirteen electrolytic capacitors: eleven surface-mount parts and two axials.<ref name="c5se" />


<templatestyles src="Template:StyledTable/styles.css" />
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:75%; text-align:center;"
|+ '''Macintosh SE/30 logic board 820-0260'''
|-
! Reference !! Capacitance !! Voltage !! Type
|-
| C1 || 47 µF || 16 V || SMD
|-
| C2 || 470 µF || 16 V || Axial
|-
| C3 || 47 µF || 16 V || SMD
|-
| C4 || 47 µF || 16 V || SMD
|-
| C5 || 47 µF || 16 V || SMD
|-
| C6 || 1 µF || 50 V || SMD
|-
| C7 || 47 µF || 16 V || SMD
|-
| C8 || 47 µF || 16 V || SMD
|-
| C9 || 47 µF || 16 V || SMD
|-
| C10 || 47 µF || 16 V || SMD
|-
| C11 || 220 µF || 16 V || Axial
|-
| C12 || 47 µF || 16 V || SMD
|-
| C13 || 47 µF || 16 V || SMD
|}
Two independent sources agree. Console5 gives the designators above;<ref name="c5se" /> Recap-a-Mac's photographic guide, made from physical boards, counts '''10&nbsp;×&nbsp;47&nbsp;µF 16&nbsp;V, 1&nbsp;×&nbsp;1&nbsp;µF 50&nbsp;V, 1&nbsp;×&nbsp;220&nbsp;µF 16&nbsp;V and 1&nbsp;×&nbsp;470&nbsp;µF 16&nbsp;V'''.<ref name="recapse30" /> The two axials are easy to overlook — they are ordinary through-hole parts, not the leaky surface-mount cans, but they are on the list.
[[File:Macintosh SE30 Logic Board Capacitors.jpg|thumb|Macintosh SE/30 logic board capacitor locations|center|587x587px]]
=== Board revisions ===
Recap-a-Mac notes a layout difference worth knowing before you follow a photograph: earlier boards have a '''socketed''' 68030; later boards have a '''dark grey soldered''' CPU, and on those the 47&nbsp;µF 16&nbsp;V capacitor near the ROM slot sits '''above''' the slot rather than below it.<ref name="recapse30" />
=== Where the damage goes ===
Two areas take the brunt, both flagged by Recap-a-Mac from repeated repairs:<ref name="recapse30" />
* '''The video multiplexer circuit''' — the row of Ux8 ICs below the large axial capacitor. Look closely for damaged traces and dried electrolyte around those pins. Faults here are common.
* '''The RAM multiplexers''' — the ICs marked "F258" above the ROM slot. If you are getting Sad Mac chimes with known-good RAM, suspect one of these rather than the memory. See [[Sad Mac Error Codes]].
Trace continuity around every capacitor should be checked with a meter before the board is powered again; a recap that leaves a broken via behind produces a machine that still does not work and a repairer who concludes, wrongly, that the recap failed.
=== Replacement parts ===
Recap-a-Mac's own choices for this board:<ref name="recapse30" />
* 1&nbsp;µF 50&nbsp;V — KEMET T491B105K050AT tantalum
* 47&nbsp;µF 16&nbsp;V — KEMET T491D476K016AT tantalum
* 220&nbsp;µF 16&nbsp;V axial — Vishay MAL213825221E3
* 470&nbsp;µF 16&nbsp;V axial — Vishay MAL211835471E3
Solid tantalum and solid polymer parts have no liquid electrolyte and cannot leak. Tantalum fails short; polymer usually fails open, which is gentler on whatever is downstream. Either is a reasonable choice here provided the voltage rating is comfortably above the rail.
== Analogue Board ==
'''The SE and SE/30 do not use the Macintosh Plus power/sweep board.''' The Plus combines supply and sweep circuitry on one board; the SE and SE/30 split them, with a separate metal-cased power supply module alongside a much smaller analogue board and a separate video board. Apple's exploded views give the same part numbers for all three modules in both machines: analogue board '''661-0371''', power supply '''661-0370''', video board '''982-0024'''.<ref name="ssse" /><ref name="ssse30" />
Thomas Lee puts the relationship precisely: on the SE and SE/30 the horizontal and video circuits are virtually identical to the Plus, but '''the vertical and power supply circuits are completely different'''.<ref name="cmrn" /> A capacitor list taken from a Plus will not match an SE.
The bare analogue board is marked '''630-0147'''. Console5 lists twelve electrolytics on it.<ref name="c5147" />
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:80%; text-align:center;"
|+ '''Macintosh SE / SE/30 analogue board 630-0147'''
|-
! Reference !! Capacitance !! Voltage !! Notes
|-
| C2 || 100 µF || 16 V ||
|-
| C7 || 100 µF || 16 V ||
|-
| C9 || 1000 µF || 16 V ||
|-
| C11 || 33 µF || 16 V ||
|-
| C13 || 220 µF || 16 V ||
|-
| C14 || 4700 µF || 16 V ||
|-
| C15 || 3.9 µF || 35 V || '''Bipolar (non-polarised), low ESR.''' See below.
|-
| C18 || 22 µF || 50 V ||
|-
| C19 || 10 µF || 160 V ||
|-
| C22 || 100 µF || 16 V ||
|-
| C24 || 220 µF || 16 V ||
|-
| C25 || 100 µF || 16 V ||
|}
=== C15 is not an ordinary capacitor ===
C15 is the high-frequency, non-polarised capacitor in the '''horizontal''' sweep circuit, and it is the single most commonly failed part on this board. Larry Pina specifies it as 3.9&nbsp;µF NP 25/35&nbsp;V HF and recommends fitting a '''3.9&nbsp;µF NP 100&nbsp;V HF''' part instead, to stop the fault returning.<ref name="dms" /> Console5 likewise flags the position as bipolar, low-ESR.<ref name="c5147" /> Do not fit an ordinary polarised electrolytic here.
Its failure sequence, from Pina:<ref name="dms" />
# Poor horizontal linearity — items on the left wider than items on the right.
# A vertical line on the right of the display a few minutes after startup, with diagonal lines; if left on, the picture darkens and the machine starts to smoke.
# Finally, a bright '''vertical''' line instead of a picture, again with smoke if left powered.
Check the yoke plug '''P1''' at the same time; Pina notes it is often burned by the time C15 has failed.
== Power Supply ==
The power supply is a separate module (Apple '''661-0370'''), and three different units were fitted. Identify yours from the label before ordering anything. Console5 publishes a list for each.<ref name="c5se" />
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+ '''Power supply: Sony CR-44M'''
|-
! Reference !! Capacitance !! Voltage
|-
| C162 || 620 µF || 400 V
|-
| C164 || 4.7 µF || 350 V
|-
| C165 || 4.7 µF || 350 V
|-
| C168 || 100 µF || 16 V
|-
| C257 || 4700 µF || 16 V
|-
| C258 || 6800 µF || 10 V
|-
| C259 || 470 µF || 16 V
|-
| C261 || 2200 µF || 16 V
|-
| C262 || 3300 µF || 10 V
|-
| C263 || 2200 µF || 16 V
|-
| C264 || 470 µF || 16 V
|-
| C265 || 47 µF || 25 V
|-
| C266 || 2200 µF || 16 V
|-
| C269 || 1 µF || 50 V
|-
| C270 || 22 µF || 25 V
|-
| C275 || 22 µF || 25 V
|-
| C276 || 22 µF || 25 V
|-
| C279 || 470 µF || 16 V
|}
{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+ '''SE/30 Analog Board Capacitor Specifications'''
|+ '''Power supply: Apple 820-0385-A / Hitachi'''
|-
|-
! Label !! Capacitance !! Voltage !! Quantity
! Reference !! Capacitance !! Voltage
|-
|-
| C1 || 3.9µF || 35V || 1x
| C101 || 10 µF || 25 V
|-
|-
| C2 || 4700µF || 16V || 1x
| C102 || 10 µF || 25 V
|-
|-
| C3 || 220µF || 16V || 2x
| C206 || 620 µF || 400 V
|-
|-
| C5 || 47µF || 10V || 1x
| C304 || 10 µF || 25 V
|-
|-
| C6 || 22µF || 50V || 2x
| C305 || 1000 µF || 25 V
|-
|-
| C10 || 33µF || 16V || 2x
| C306 || 470 µF || 16 V
|-
|-
| C11 || 10µF || 160V || 1x
| C307 || 1000 µF || 10 V
|-
|-
| C12 || 22µF || 50V || 2x
| C308 || 4700 µF || 10 V
|-
|-
| C18 || 33µF || 16V || 2x
| C309 || 1000 µF || 16 V
|-
|-
| C24 || 2200µF || 16V || 4x
| C310 || 1000 µF || 16 V
|-
|-
| C27 || 2200µF || 16V || 1x
| C311 || 470 µF || 16 V
|-
|-
| C28 || 1000µF || 16V || 1x
| C312 || 470 µF || 16 V
|-
| C401 || 100 µF || 25 V
|-
| C402 || 10 µF || 25 V
|-
| C404 || 22 µF || 16 V
|-
| C408 || 10 µF || 25 V
|-
| C412 || 100 µF || 10 V
|}
 
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+ '''Power supply: Apple 699-5047 / ASTEC AA13800'''
|-
|-
| C30 || 2200µF || 16V || 1x
! Reference !! Capacitance !! Voltage
|-
|-
| C31 || 220µF || 16V || 1x
| C7 || 330 µF || 200 V
|-
|-
| C32 || 2200µF || 16V || 1x
| C8 || 330 µF || 200 V
|-
|-
| C33 || 4700pF || 250V || 2x
| C19 || 220 µF || 25 V
|-
|-
| C34 || 100µF || 200V || 4x
| C21 || 47 µF || 63 V
|-
|-
| C35 || 100µF || 200V || 1x
| C23 or C25 || 470 µF || 16 V
|-
|-
| C36 || 4700pF || 250V || 1x
| C24 || 1200 µF || 10 V
|-
|-
| C37 || 0.47µF || 250V || 1x
| C25 or C28 || 220 µF || 16 V
|-
|-
| C38 || 100µF || 200V || 1x
| C31 || 2200 µF || 16 V
|-
|-
| C39 || 100µF || 200V || 1x
| C32 || 47 µF || 25 V
|-
|-
| C42 || 470µF || 10V || 2x
| C35 || 470 µF || 16 V
|-
|-
| C45 || 470µF || 10V || 1x
| C36 || 1200 µF || 10 V
|}
|}


=== 🔧 Logic Board Capacitors ===
Console5 notes that some — not all — ASTEC supplies were built with three 4700&nbsp;pF metallised-paper RIFA Y-class safety capacitors, and that these should always be replaced when found.<ref name="c5se" /> The ambiguous designators in that last table ("C23 or C25", "C25 or C28") are reproduced as published; check your own board's silkscreen.
The SE/30 logic board is particularly prone to capacitor failure and corrosion, making recapping especially important.
 
Note the primary-side ratings: 620&nbsp;µF 400&nbsp;V in the Sony and Hitachi units, and a series pair of 330&nbsp;µF 200&nbsp;V in the ASTEC. Those parts sit at rectified mains potential and hold charge after power-off.
 
=== There is no voltage adjustment ===
 
Apple's Service Source for this machine contains Yoke and Video adjustment procedures and '''nothing else''' — no voltage adjustment, and no rail tolerances.<ref name="APPLESS" /> The adjustable trimmer R56 belongs to the Macintosh 128K/512K/Plus power/sweep board, which is a different board in a different machine;<ref name="cmrn" /> there is no equivalent control here. The video controls on the SE and SE/30 analogue board are brightness, width, height and focus.<ref name="APPLESS" />


<templatestyles src="Template:StyledTable/styles.css" />
If the rails are out of specification on one of these machines, the supply module is at fault and needs repair or replacement — there is nothing to turn.
{| class="wikitable styled-table" style="width:100%; text-align:center;"
 
|+ '''SE/30 Logic Board Capacitor Specifications'''
== Analogue Board Faults by Component ==
 
Larry Pina's ''The Dead Mac Scrolls'' documents the analogue-board faults of the SE and SE/30 down to individual components, with exact replacement specifications. It is hosted on this wiki.<ref name="dms" />
 
{| class="wikitable styled-table" style="width:100%;"
|-
! Symptom !! Component !! Specification
|-
| No chime, dark display, a dreadful hissing or sizzling noise || '''CR2''' shorted (0.00–0.01&nbsp;Ω) || Barrel rectifier GI854, R-51, 600&nbsp;V 3&nbsp;A. Pina suggests an MR824 (R-51, 400&nbsp;V, 5&nbsp;A) as a heavier-duty replacement.
|-
| No chime, dark display, apparently completely dead, '''no''' hissing noise || '''CR3''' shorted; then '''Q2''' burned; then flyback '''T2''' || CR3 is the same GI854 barrel rectifier. Q2 is the BU4060 horizontal output transistor.
|-
| Right side of the picture shakes in and out during disk access or when a window opens || '''CR2''', then '''Q2''' || As above
|-
|-
! Label !! Capacitance !! Voltage !! Quantity
| Chimes, fan turns, hard disk spins, but the display stays dark and the brightness control does nothing || '''R22''' open || 470&nbsp;kΩ, ½&nbsp;W, 5&nbsp;%
|-
|-
| C1 – C10 || 47µF || 16V || 10x
| Chimes, then a relatively dim '''vertical''' line || '''R19''' burned || 220&nbsp;Ω, ½&nbsp;W, 5&nbsp;%. Vacuum-desolder and resolder linearity coil '''L3''' with fresh solder, or it will recur.
|-
|-
| C11 || 1µF || 50V || 1x
| Poor horizontal linearity, then a bright '''vertical''' line and smoke || '''C15''', and yoke plug '''P1''' || 3.9&nbsp;µF NP 25/35&nbsp;V HF; fit 3.9&nbsp;µF NP 100&nbsp;V HF
|}
|}


[[File:Macintosh SE30 Logic Board Capacitors.jpg|thumb|Macintosh SE/30 Logic Board Capacitor Locations|center|587x587px]]
A '''single vertical line''' is a horizontal sweep collapse — C15, R19, L3 or the yoke plug. A '''single horizontal line''' is a vertical sweep collapse, a different circuit built around the TDA1170 vertical deflection IC.<ref name="cmrn" /> In either case switch off at once; a concentrated line burns the phosphor within minutes.


== 🛠️ Capacitor Replacement Procedure ==
== Capacitor Replacement Procedure ==


# '''Discharge the CRT''' – Follow standard CRT discharge procedures before working inside.
# '''Remove the logic board''' and take the battery off it.
# '''Remove the Logic & Analog Boards''' – Label cables and safely extract both boards.
# '''Remove the old surface-mount capacitors.''' Alternate heat between the two terminals while gently tilting the can, or use hot air with the surrounding plastic shielded. Twisting a can off cold will take the pads with it.
# '''Desolder Old Capacitors''' – Use a quality soldering iron, braid, or pump to remove components cleanly.
# '''Clean thoroughly.''' Isopropyl alcohol and a soft brush over the whole area, repeatedly, until no residue transfers to a clean swab.
# '''Install New Capacitors''' – Insert with correct polarity (check for stripe on negative side).
# '''Inspect and test.''' Check continuity across every trace that ran under or beside a capacitor. Repair breaks with fine wire before fitting anything new.
# '''Solder Carefully''' – Ensure clean, shiny joints without cold solder bridges.
# '''Fit the new parts''' the right way round. On a tantalum the stripe marks '''positive'''; on an aluminium electrolytic it marks '''negative'''. This catches people out.
# '''Trim Leads & Inspect Work''' – Cut excess and examine under light or magnification.
# '''Check for shorts''' across each rail before applying power.
# '''Test for Shorts''' – Use a multimeter to confirm there are no shorts across power rails.
# '''Discharge the CRT''' before starting on the analogue board, if you are going that far.


== 🧰 Recommended Tools ==
Tools are listed on [[Recommended Tools]].


* Temperature-controlled soldering iron (fine tip)
== Module Part Numbers ==
* Desoldering braid or vacuum pump
* Quality leaded solder (0.5 mm recommended)
* Isopropyl alcohol and ESD brush
* Multimeter
* Safety goggles and insulated gloves


== ⚙️ Voltage Adjustment After Recap ==
From Apple's exploded view for the Macintosh SE/30:<ref name="APPLESS" />


Measure voltages at the floppy drive or logic board power connector:
* Analogue board — '''661-0371''' (shared with the SE)
* Power supply — '''661-0370''' (shared with the SE)
* Video board — '''982-0024''' (shared with the SE)
* Logic board — '''661-0527'''
* CRT and yoke assembly — 076-0103
* Front bezel — 630-5499


* '''+5V rail:''' 4.85V – 5.15V
== What Apple published, and what it did not ==
* '''+12V rail:''' 11.9V – 12.7V


Use the analog board's '''trimmer potentiometer (R56)''' to fine-tune if necessary.
Apple's own [[Macintosh SE/30 Service Source]] is '''module level'''. It has no parts list, no schematic and no component values; its Adjustments chapter is Yoke and Video only, so there is '''no voltage adjustment''' on this machine; and its battery threshold is '''replace below 2.8&nbsp;V''', measured with the cover off, '''the CRT discharged''' and the logic board removed.<ref name="ssse3089">Apple Computer, ''Macintosh SE/30'' Service Source, 89 pp, PDF distilled 5 December 1995. Hosted here as [[Macintosh SE/30 Service Source]] ([[:File:Macintosh SE30.pdf]]). Specifications — Electrical; Additional Procedures — Battery Verification; Adjustments.</ref>


== 💡 Tips for Best Results ==
One file on this wiki is relevant here and is easy to misread: '''[[:File:Classic Analog Board Schematic.pdf]]''' carries the internal document title '''SE30_Analog_Board''' and shows a hard-disk power connector the Macintosh Classic does not have. Read it as an SE/30 document.


* Always recap the logic board first – leaking caps often cause corrosion damage.
== Related Pages ==
* Use quality capacitors (e.g., Nichicon, Panasonic, Rubycon).
* Turn on the system periodically to prolong capacitor lifespan.
* Replace in full sets for even aging and reliability.
* Clean the board thoroughly with isopropyl alcohol after removal.


== 🔗 Related Pages ==
* [[Macintosh SE/30 Service Source]]
* [[The Dead Mac Scrolls]] — chapter 2 covers the SE and SE/30
* [[Macintosh Repair & Upgrade Secrets]] — the compact-Mac analogue-board parts lists
* [[Macintosh SE/30]]
* [[Macintosh SE/30 General Maintenance]]
* [[Macintosh SE/30 General Maintenance]]
* [[Macintosh SE/30 Troubleshooting]]
* [[Macintosh SE/30 Troubleshooting]]
* [[Macintosh SE Capacitor Replacement Guide]]
* [[Macintosh SE/30 Logic Board Schematic]]
* [[Battery Explosion, Capacitor or Corrosion Damage]]
* [[Capacitor Failure Symptoms]]
* [[CRT Discharge Procedure]]
* [[CRT Discharge Procedure]]
* [[Recommended Tools]]
* [[Sad Mac Error Codes]]
== References ==
<references>
<ref name="APPLESS">Apple Computer, ''Macintosh SE/30 Service Source'', hosted here as [[:File:Macintosh SE30.pdf]]. Specifications (Electrical, PRAM), Additional Procedures — Battery Verification, Adjustments (Yoke and Video only) and the Exploded View parts list. Apple's Service Source is module-level: procedures, thresholds and field-replaceable-unit numbers, not component values.</ref>
<ref name="ssse">Apple Computer, ''Macintosh SE Service Source'', Exploded View — analogue board 661-0371, power supply 661-0370, video board 982-0024. [[:File:Macintosh_SE.pdf]]</ref>
<ref name="ssse30">Apple Computer, ''Macintosh SE/30 Service Source'', Exploded View — the same three module part numbers. [[:File:Macintosh SE30.pdf]]</ref>
<ref name="c5se">Console5 TechWiki, "Macintosh SE" (the SE/30 redirects here) — SE/30 logic board 820-0260, analogue board 630-0147 and the three power supply variants. https://wiki.console5.com/wiki/Macintosh_SE Secondary source — vendor cap-kit lists, not Apple documentation.</ref>
<ref name="c5147">Console5 TechWiki, "Mac Analog Board: 630-0147". https://wiki.console5.com/wiki/Mac_Analog_Board:_630-0147 Secondary source.</ref>
<ref name="recapse30">Bruce / Recap-a-Mac, "Macintosh SE/30". https://recapamac.com.au/macintosh-se-30/ Capacitor counts and replacement part numbers from a photographic recapping guide; the socketed-versus-soldered CPU revision difference; the Ux8 video multiplexer and F258 RAM multiplexer failures. Secondary source, derived from recapping these machines in practice.</ref>
<ref name="dms">Larry Pina, ''The Dead Mac Scrolls'' (1992), hosted here as [[:File:The Dead Mac Scrolls 1992.pdf]], "Mac SE and SE/30" section. Symptom-to-component diagnoses with exact part specifications.</ref>
<ref name="cmrn">Thomas H. Lee, ''Classic Mac Repair Notes'', revision of 31 May 2007 (©2000 Thomas H. Lee, all rights reserved; not re-hosted here for that reason). https://archive.org/details/Classic_Mac_Repair_Notes Section 1.0 on which circuits the SE and SE/30 share with the Plus, and section 7.3 on the TDA1170 vertical deflection IC.</ref>
</references>


[[Category:Apple Vintage Computers]]
[[Category:Apple Vintage Computers]]
[[Category:Apple Maintenance Guides]]
[[Category:Capacitor Replacement Guides]]
[[Category: Capacitor Replacement Guides]]

Latest revision as of 08:48, 25 September 2026

Every Macintosh SE/30 has leaking capacitors. Not most — all of them. The surface-mount electrolytics on the logic board vent a conductive, corrosive electrolyte that creeps under adjacent ICs and eats traces and vias, and the longer a board is left the greater the chance the damage goes beyond what a recap will fix.[1] This is the single most important fact about the machine, and it is why the logic board comes first on this page and the analogue board second.

Safety

[edit | edit source]

Do the Battery First

[edit | edit source]

Remove or check the 1/2 AA lithium PRAM cell before anything else. Apple's procedure is to remove the logic board, measure across the cell on the 10 V DC range and replace it if it reads below 2.8 V.[3] A leaked cell produces exactly the same kind of trace damage as a leaked capacitor, in the same part of the board. See Battery Explosion, Capacitor or Corrosion Damage.

Capacitor Inspection

[edit | edit source]

On an SE/30 the question is not whether the capacitors have leaked but how far the electrolyte has travelled.

  • Dark haloes or dried crust around the base of the surface-mount cans.
  • Dull, grey or green solder joints on nearby IC pins — electrolyte attacks the joint before it attacks the trace.
  • Missing or thinned traces near the capacitors, best seen under a loupe with light across the board.
  • Bulging tops are not a reliable sign on these parts; they usually leak from the base without deforming.

See Capacitor Failure Symptoms.

Logic Board

[edit | edit source]

The SE/30 logic board, Apple part 820-0260, carries thirteen electrolytic capacitors: eleven surface-mount parts and two axials.[2]

Macintosh SE/30 logic board 820-0260
Reference Capacitance Voltage Type
C1 47 µF 16 V SMD
C2 470 µF 16 V Axial
C3 47 µF 16 V SMD
C4 47 µF 16 V SMD
C5 47 µF 16 V SMD
C6 1 µF 50 V SMD
C7 47 µF 16 V SMD
C8 47 µF 16 V SMD
C9 47 µF 16 V SMD
C10 47 µF 16 V SMD
C11 220 µF 16 V Axial
C12 47 µF 16 V SMD
C13 47 µF 16 V SMD

Two independent sources agree. Console5 gives the designators above;[2] Recap-a-Mac's photographic guide, made from physical boards, counts 10 × 47 µF 16 V, 1 × 1 µF 50 V, 1 × 220 µF 16 V and 1 × 470 µF 16 V.[1] The two axials are easy to overlook — they are ordinary through-hole parts, not the leaky surface-mount cans, but they are on the list.

Macintosh SE/30 logic board capacitor locations

Board revisions

[edit | edit source]

Recap-a-Mac notes a layout difference worth knowing before you follow a photograph: earlier boards have a socketed 68030; later boards have a dark grey soldered CPU, and on those the 47 µF 16 V capacitor near the ROM slot sits above the slot rather than below it.[1]

Where the damage goes

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Two areas take the brunt, both flagged by Recap-a-Mac from repeated repairs:[1]

  • The video multiplexer circuit — the row of Ux8 ICs below the large axial capacitor. Look closely for damaged traces and dried electrolyte around those pins. Faults here are common.
  • The RAM multiplexers — the ICs marked "F258" above the ROM slot. If you are getting Sad Mac chimes with known-good RAM, suspect one of these rather than the memory. See Sad Mac Error Codes.

Trace continuity around every capacitor should be checked with a meter before the board is powered again; a recap that leaves a broken via behind produces a machine that still does not work and a repairer who concludes, wrongly, that the recap failed.

Replacement parts

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Recap-a-Mac's own choices for this board:[1]

  • 1 µF 50 V — KEMET T491B105K050AT tantalum
  • 47 µF 16 V — KEMET T491D476K016AT tantalum
  • 220 µF 16 V axial — Vishay MAL213825221E3
  • 470 µF 16 V axial — Vishay MAL211835471E3

Solid tantalum and solid polymer parts have no liquid electrolyte and cannot leak. Tantalum fails short; polymer usually fails open, which is gentler on whatever is downstream. Either is a reasonable choice here provided the voltage rating is comfortably above the rail.

Analogue Board

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The SE and SE/30 do not use the Macintosh Plus power/sweep board. The Plus combines supply and sweep circuitry on one board; the SE and SE/30 split them, with a separate metal-cased power supply module alongside a much smaller analogue board and a separate video board. Apple's exploded views give the same part numbers for all three modules in both machines: analogue board 661-0371, power supply 661-0370, video board 982-0024.[4][5]

Thomas Lee puts the relationship precisely: on the SE and SE/30 the horizontal and video circuits are virtually identical to the Plus, but the vertical and power supply circuits are completely different.[6] A capacitor list taken from a Plus will not match an SE.

The bare analogue board is marked 630-0147. Console5 lists twelve electrolytics on it.[7]

Macintosh SE / SE/30 analogue board 630-0147
Reference Capacitance Voltage Notes
C2 100 µF 16 V
C7 100 µF 16 V
C9 1000 µF 16 V
C11 33 µF 16 V
C13 220 µF 16 V
C14 4700 µF 16 V
C15 3.9 µF 35 V Bipolar (non-polarised), low ESR. See below.
C18 22 µF 50 V
C19 10 µF 160 V
C22 100 µF 16 V
C24 220 µF 16 V
C25 100 µF 16 V

C15 is not an ordinary capacitor

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C15 is the high-frequency, non-polarised capacitor in the horizontal sweep circuit, and it is the single most commonly failed part on this board. Larry Pina specifies it as 3.9 µF NP 25/35 V HF and recommends fitting a 3.9 µF NP 100 V HF part instead, to stop the fault returning.[8] Console5 likewise flags the position as bipolar, low-ESR.[7] Do not fit an ordinary polarised electrolytic here.

Its failure sequence, from Pina:[8]

  1. Poor horizontal linearity — items on the left wider than items on the right.
  2. A vertical line on the right of the display a few minutes after startup, with diagonal lines; if left on, the picture darkens and the machine starts to smoke.
  3. Finally, a bright vertical line instead of a picture, again with smoke if left powered.

Check the yoke plug P1 at the same time; Pina notes it is often burned by the time C15 has failed.

Power Supply

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The power supply is a separate module (Apple 661-0370), and three different units were fitted. Identify yours from the label before ordering anything. Console5 publishes a list for each.[2]

Power supply: Sony CR-44M
Reference Capacitance Voltage
C162 620 µF 400 V
C164 4.7 µF 350 V
C165 4.7 µF 350 V
C168 100 µF 16 V
C257 4700 µF 16 V
C258 6800 µF 10 V
C259 470 µF 16 V
C261 2200 µF 16 V
C262 3300 µF 10 V
C263 2200 µF 16 V
C264 470 µF 16 V
C265 47 µF 25 V
C266 2200 µF 16 V
C269 1 µF 50 V
C270 22 µF 25 V
C275 22 µF 25 V
C276 22 µF 25 V
C279 470 µF 16 V
Power supply: Apple 820-0385-A / Hitachi
Reference Capacitance Voltage
C101 10 µF 25 V
C102 10 µF 25 V
C206 620 µF 400 V
C304 10 µF 25 V
C305 1000 µF 25 V
C306 470 µF 16 V
C307 1000 µF 10 V
C308 4700 µF 10 V
C309 1000 µF 16 V
C310 1000 µF 16 V
C311 470 µF 16 V
C312 470 µF 16 V
C401 100 µF 25 V
C402 10 µF 25 V
C404 22 µF 16 V
C408 10 µF 25 V
C412 100 µF 10 V
Power supply: Apple 699-5047 / ASTEC AA13800
Reference Capacitance Voltage
C7 330 µF 200 V
C8 330 µF 200 V
C19 220 µF 25 V
C21 47 µF 63 V
C23 or C25 470 µF 16 V
C24 1200 µF 10 V
C25 or C28 220 µF 16 V
C31 2200 µF 16 V
C32 47 µF 25 V
C35 470 µF 16 V
C36 1200 µF 10 V

Console5 notes that some — not all — ASTEC supplies were built with three 4700 pF metallised-paper RIFA Y-class safety capacitors, and that these should always be replaced when found.[2] The ambiguous designators in that last table ("C23 or C25", "C25 or C28") are reproduced as published; check your own board's silkscreen.

Note the primary-side ratings: 620 µF 400 V in the Sony and Hitachi units, and a series pair of 330 µF 200 V in the ASTEC. Those parts sit at rectified mains potential and hold charge after power-off.

There is no voltage adjustment

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Apple's Service Source for this machine contains Yoke and Video adjustment procedures and nothing else — no voltage adjustment, and no rail tolerances.[3] The adjustable trimmer R56 belongs to the Macintosh 128K/512K/Plus power/sweep board, which is a different board in a different machine;[6] there is no equivalent control here. The video controls on the SE and SE/30 analogue board are brightness, width, height and focus.[3]

If the rails are out of specification on one of these machines, the supply module is at fault and needs repair or replacement — there is nothing to turn.

Analogue Board Faults by Component

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Larry Pina's The Dead Mac Scrolls documents the analogue-board faults of the SE and SE/30 down to individual components, with exact replacement specifications. It is hosted on this wiki.[8]

Symptom Component Specification
No chime, dark display, a dreadful hissing or sizzling noise CR2 shorted (0.00–0.01 Ω) Barrel rectifier GI854, R-51, 600 V 3 A. Pina suggests an MR824 (R-51, 400 V, 5 A) as a heavier-duty replacement.
No chime, dark display, apparently completely dead, no hissing noise CR3 shorted; then Q2 burned; then flyback T2 CR3 is the same GI854 barrel rectifier. Q2 is the BU4060 horizontal output transistor.
Right side of the picture shakes in and out during disk access or when a window opens CR2, then Q2 As above
Chimes, fan turns, hard disk spins, but the display stays dark and the brightness control does nothing R22 open 470 kΩ, ½ W, 5 %
Chimes, then a relatively dim vertical line R19 burned 220 Ω, ½ W, 5 %. Vacuum-desolder and resolder linearity coil L3 with fresh solder, or it will recur.
Poor horizontal linearity, then a bright vertical line and smoke C15, and yoke plug P1 3.9 µF NP 25/35 V HF; fit 3.9 µF NP 100 V HF

A single vertical line is a horizontal sweep collapse — C15, R19, L3 or the yoke plug. A single horizontal line is a vertical sweep collapse, a different circuit built around the TDA1170 vertical deflection IC.[6] In either case switch off at once; a concentrated line burns the phosphor within minutes.

Capacitor Replacement Procedure

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  1. Remove the logic board and take the battery off it.
  2. Remove the old surface-mount capacitors. Alternate heat between the two terminals while gently tilting the can, or use hot air with the surrounding plastic shielded. Twisting a can off cold will take the pads with it.
  3. Clean thoroughly. Isopropyl alcohol and a soft brush over the whole area, repeatedly, until no residue transfers to a clean swab.
  4. Inspect and test. Check continuity across every trace that ran under or beside a capacitor. Repair breaks with fine wire before fitting anything new.
  5. Fit the new parts the right way round. On a tantalum the stripe marks positive; on an aluminium electrolytic it marks negative. This catches people out.
  6. Check for shorts across each rail before applying power.
  7. Discharge the CRT before starting on the analogue board, if you are going that far.

Tools are listed on Recommended Tools.

Module Part Numbers

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From Apple's exploded view for the Macintosh SE/30:[3]

  • Analogue board — 661-0371 (shared with the SE)
  • Power supply — 661-0370 (shared with the SE)
  • Video board — 982-0024 (shared with the SE)
  • Logic board — 661-0527
  • CRT and yoke assembly — 076-0103
  • Front bezel — 630-5499

What Apple published, and what it did not

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Apple's own Macintosh SE/30 Service Source is module level. It has no parts list, no schematic and no component values; its Adjustments chapter is Yoke and Video only, so there is no voltage adjustment on this machine; and its battery threshold is replace below 2.8 V, measured with the cover off, the CRT discharged and the logic board removed.[9]

One file on this wiki is relevant here and is easy to misread: File:Classic Analog Board Schematic.pdf carries the internal document title SE30_Analog_Board and shows a hard-disk power connector the Macintosh Classic does not have. Read it as an SE/30 document.

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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 Bruce / Recap-a-Mac, "Macintosh SE/30". https://recapamac.com.au/macintosh-se-30/ Capacitor counts and replacement part numbers from a photographic recapping guide; the socketed-versus-soldered CPU revision difference; the Ux8 video multiplexer and F258 RAM multiplexer failures. Secondary source, derived from recapping these machines in practice.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Console5 TechWiki, "Macintosh SE" (the SE/30 redirects here) — SE/30 logic board 820-0260, analogue board 630-0147 and the three power supply variants. https://wiki.console5.com/wiki/Macintosh_SE Secondary source — vendor cap-kit lists, not Apple documentation.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Apple Computer, Macintosh SE/30 Service Source, hosted here as File:Macintosh SE30.pdf. Specifications (Electrical, PRAM), Additional Procedures — Battery Verification, Adjustments (Yoke and Video only) and the Exploded View parts list. Apple's Service Source is module-level: procedures, thresholds and field-replaceable-unit numbers, not component values.
  4. ↑ Apple Computer, Macintosh SE Service Source, Exploded View — analogue board 661-0371, power supply 661-0370, video board 982-0024. File:Macintosh_SE.pdf
  5. ↑ Apple Computer, Macintosh SE/30 Service Source, Exploded View — the same three module part numbers. File:Macintosh SE30.pdf
  6. ↑ 6.0 6.1 6.2 Thomas H. Lee, Classic Mac Repair Notes, revision of 31 May 2007 (©2000 Thomas H. Lee, all rights reserved; not re-hosted here for that reason). https://archive.org/details/Classic_Mac_Repair_Notes Section 1.0 on which circuits the SE and SE/30 share with the Plus, and section 7.3 on the TDA1170 vertical deflection IC.
  7. ↑ 7.0 7.1 Console5 TechWiki, "Mac Analog Board: 630-0147". https://wiki.console5.com/wiki/Mac_Analog_Board:_630-0147 Secondary source.
  8. ↑ 8.0 8.1 8.2 Larry Pina, The Dead Mac Scrolls (1992), hosted here as File:The Dead Mac Scrolls 1992.pdf, "Mac SE and SE/30" section. Symptom-to-component diagnoses with exact part specifications.
  9. ↑ Apple Computer, Macintosh SE/30 Service Source, 89 pp, PDF distilled 5 December 1995. Hosted here as Macintosh SE/30 Service Source (File:Macintosh SE30.pdf). Specifications — Electrical; Additional Procedures — Battery Verification; Adjustments.
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