Macintosh SE Capacitor Replacement Guide

The Macintosh SE logic board is not one of the Macs that leaks. Its capacitors are the older axial type rather than the surface-mount parts that destroy SE/30, Classic and Classic II boards, and Recap-a-Mac — which has recapped a great many compact Macs — says the SE very rarely needs recapping at all. The parts that do need attention are the on-board lithium battery, the analogue board and the power supply.

Do the Battery First

The SE keeps PRAM alive with a soldered 1/2 AA lithium cell, which Apple describes as a "seven-year lithium battery". It is now several times that age. Apple's own verification 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.

A leaking cell will take traces with it. See Battery Explosion, Capacitor or Corrosion Damage.

Capacitor Inspection

• Bulging tops — a healthy capacitor has a flat top.
• Leaking electrolyte — brown or white crust at the leads.
• Corrosion or board staining near the base of a capacitor.

An ESR meter is more use than a capacitance meter here: these parts usually fail by drying out and going high-ESR rather than by losing capacitance. See Capacitor Failure Symptoms.

Logic Board

The SE logic board — Apple part 820-0176 or 820-0250 depending on revision — carries eleven electrolytic capacitors.

Macintosh SE logic board 820-0176 / 820-0250

Reference	Capacitance	Voltage
C4	33 µF	16 V
C11	33 µF	16 V
C13	33 µF	16 V
C16	33 µF	16 V
C32	33 µF	16 V
C34	33 µF	16 V
C36	1 µF	50 V
C37	33 µF	16 V
C38	33 µF	16 V
C62	33 µF	16 V
C86	33 µF	16 V

Two independent sources agree on the totals: Console5 lists the ten 33 µF 16 V positions and one 1 µF 50 V position above, and Recap-a-Mac's photographic guide, made from a physical SE board, counts exactly 10 × 33 µF 16 V and 1 × 1 µF 50 V.

Macintosh SE logic board capacitor locations

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.

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. 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.

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 µF NP 25/35 V HF and recommends fitting a 3.9 µF NP 100 V HF part instead, to stop the fault returning. Console5 likewise flags the position as bipolar, low-ESR. Do not fit an ordinary polarised electrolytic here.

Its failure sequence, from Pina:

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

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.

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. 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

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

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

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.

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

Two of those deserve emphasis. A single vertical line is a collapse of the horizontal sweep and points at C15, R19, L3 or the yoke plug. A single horizontal line is a collapse of the vertical sweep — a different circuit, built around the TDA1170 vertical deflection IC that Apple adopted on the compact Macs after the Plus. Either way, switch the machine off immediately: a concentrated line will burn the phosphor in minutes.

Capacitor Replacement Procedure

1. Discharge the CRT — see CRT Discharge Procedure.
2. Remove the battery from the logic board before cleaning or reworking it.
3. Confirm the primary-side capacitors in the power supply are discharged before opening it.
4. Photograph each board before removing anything.
5. Desolder with a temperature-controlled iron and wick or a pump.
6. Clean the pads and check for corrosion underneath each old part.
7. Fit the new parts the right way round — stripe to negative. C15 on the analogue board is non-polarised.
8. Inspect under magnification for bridges and cold joints.
9. Check for shorts across each rail before applying power.

Tools are listed on Recommended Tools.

Module Part Numbers

From Apple's exploded view for the Macintosh SE:

• Analogue board — 661-0371 (shared with the SE/30)
• Power supply — 661-0370 (shared with the SE/30)
• Video board — 982-0024 (shared with the SE/30)
• Logic board — 661-0530
• CRT and yoke assembly — 076-0103
• Chassis — 805-0938

Choosing Replacements

• 105 °C-rated parts from a known manufacturer for anything in the power supply or on the analogue board.
• Match or exceed the rating printed on the part you removed.
• Never substitute a polarised part for C15.
• Replace metallised-paper (RIFA) safety capacitors on sight.

Component-level sources held on this wiki

Apple's own Macintosh SE Service Source is module level: the analogue board and power supply are one replaceable assembly, and the volume carries no parts list and no component values. It also confirms there is no voltage adjustment on this machine — its Adjustments chapter is Yoke and Video only — and gives the battery threshold as replace below 2.8 V, measured with the cover off, the CRT discharged and the logic board removed.

Component-level data for this machine is in Larry Pina's 1990 book, held here as Macintosh Repair & Upgrade Secrets, which devotes chapter 14 to SE repair and prints two parts lists for it: Appendix E, the Macintosh SE analogue board, and Appendix F, the SE CRT socket board — the smaller board on the neck of the tube, which no other source here enumerates. Appendix E also identifies the tube as a Samsung type 10ATY4N white antiglare CRT.

Related Pages

• Macintosh Repair & Upgrade Secrets
• The Dead Mac Scrolls — chapter 2 covers the SE and SE/30
• Macintosh SE Service Source
• Macintosh SE
• Macintosh SE Troubleshooting
• Macintosh SE General Maintenance
• Macintosh SE/30 Capacitor Replacement Guide
• Battery Explosion, Capacitor or Corrosion Damage
• Capacitor Failure Symptoms
• CRT Discharge Procedure
• Recommended Tools