Classic Mac RepairResources

I. Disassemble the Mac SE/30 Box

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1. Caution and Warning

Before working inside the Macintosh SE/30, turnoff the power and disconnect the AC power cord.
The SE/30 contains high voltage (1,500 Volts), a high-vacuum cathoderay tube (CRT) and sensitive electronic parts.
To prevent serious injury, the first thing you have to do is todischarge the CRT. Discharging the CRT before working on it lessensthe chance of an electric shock.
Some later compact Macs containing CRTs have a bleeder resistor onthe anode that drains the charge when the power is turned off.However, if the resistor fails, the anode may retain a charge. Thus,you must perform the discharge procedure.
Never touch the anode connector or the anode aperture, that canregain some charge even after it has been discharged.
Secondly, you must be careful not to break the fragile CRT neck. Donot pick up or handle a CRT by its neck, where the tube is thethinnest. To prevent an implosion, take every precaution againstbreaking the CRT. Wearing safety goggles is preferred when workingwith a CRT. The CRT contains a high vacuum. If cracked or broken, theCRT can implode (collapse into itself) and scatter fragments ofglass.
Thirdly, precautions are required not to break IC and LSI chips onthe board by electrostatic damages.
Go ahead at your own risk. Nobody can take responsibility foryou.

2. Take apart SE/30

Tools required:
1. long Torx T-15 screwdriver
2. small (minus or plus) screwdriver
3. pull-apart tool (a.k.a. case opener, case spreader or casecracker)
4. discharge tool
One of my pull-apart tools is simply a spring clamp marked 'Pony 3201Made in USA'. I bought a Mac opener kit from APS long ago. This Macopener kit consisted of a long Torx driver, a pull-apart tool and agrounding wrist strap. The jaws (closed) of the clamp measure 3/4inch (19 mm) wide and 1/16 inch (1.6 mm) thick. Just insert the jawsand squeeze. You can find a similar tool at any hardware or hobbyistshop or Home Depot or Office Depot. Instead of the pull-apart tool,you can use a medium to long flat-blade screwdriver to open thecomputer's case. But use it carefully not to damage the case.
You can also find a long Torx T-15 screwdriver at any hardware orhobbyist shop, Home Depot or Office Depot.
(1) Using a small screwdriver, pry off the reset/interrupt switch onthe left side of the case.
(2) Using a long Torx screwdriver, remove the four case screws andseparate the rear housing cover from the chassis with a pull-aparttool.
(3) Carefully lift up the rear housing cover and set it aside.
(4) Remove the paper insulating shroud from the bottom of thecomputer. It may come out with the rear housing cover.

Replacement Note:
Reinstall the two black case screws in the bottom of the cover andthe two silver-colored case screws in the top of the cover.

3. Discharge CRT

If you are working on a compact Mac that containsa CRT (just like SE/30) and incorrectly discharge the CRT to themetal chassis, you may destroy the logic board.
You must discharge to the ground lug!
YOU MUST DISCHARGE TO THE GROUND LUG!
(1) Attach the clip of the CRT discharge tool to the ground lug ofthe Mac.
(2) Touch the discharge tool probe to the anode aperture.
(2-1) Put one hand behind your back, and grasp the handle of thedischarge tool with your otherhand.
(2-2) Hold the CRT discharge tool to the tube surface, and slide thetool probe under the anode cap until the probe touches the anodeaperture.
(2-3) Remove the probe of the CRT discharge tool from under the anodecap.

4. Discharge Tool

Tool For Opening A Mac Plus Minus

There are two official CRT discharge toolsdistributed by Apple.
One version is the Apple CRT Discharge Tool (Part No. 076-0381) forlater compact Macs and monitors. This version features a stainlesssteel alligator clip, thicker insulation, and a hand guard. Nointernal resistor is installed, so the tool gives auditory feedback(the electrostatic crack) to assure the technician, when dischargingany monitor without a bleeder resistor, that the CRT is indeeddischarged.
The other one is the older version of the Apple CRT Discharge Tool(Part No. 076-0243). The older version has a copper alligator clipbut no hand guard. It has a built-in 100-megohm resistor, which meansyou will not hear an electrostatic crack when the CRT discharges,even if the monitor has no bleeder resistor. This older tool wasdesigned for the original Macintosh or Macintosh Plus logic board. Aresistor was installed to diminish the impact of the electrostaticdischarge if a technician accidentally discharged the CRT to themetal chassis instead of to the ground lug. (The Macintosh logicboard circuitry is grounded to the chassis.) This older tool is saferfor use on the Macintosh or Macintosh Plus CRT.
Getting these official Apple tools is difficult, unless you are anApple authorized technician
But you can make a discharge tool with a screwdriver, clips, a 100(or 10) meg ohm resistor, a ballpoint pen shaft (the outer tube of aballpoint pen) and some wires. Insulating the resistor and its leadswith the ballpoint pen shaft prevents careless short between theanode and other components.
The Simple Model and the Built-in Resistor Model in the left figureare corresponding to the Apple Newer and Older Discharge Tools,respectively.

5. Bleeder Resister and FlybackTransformer

The high voltage (1,500 Volts) on the anode of theCRT is supplied by the flyback transformer on the analog board. Donot touch the flyback transformer. Do not touch the yoke assembly,yoke cable/connector, high voltage cable and anode connector,either.
Several flyback transformers have been used for compact Macs as shownTable below.
Normally, Macintosh SE/30 contains a flyback transformer with abuilt-in bleeder resistor, and it automatically discharges thetransformer, i.e., CRT when the power is shut off. However, oldand/or used SE/30s may have been modified or repaired. The flybacktransformer may be replaced by an older version. Thus, for yoursafety, you must perform CRT discharge procedures.

II. Trouble Shooting

1. SimasiMac (Horizontal Stripes)

Simasima means a zebra-like stripe pattern in Japanese.OYU!(HHD00612@niftyserve.ne.jp) and ShunsukeSuzuki(VZD03711@niftyserve.ne.jp) nicely named Macintosh SE/30 withthis problem SimasiMac. We SE/30ers in Japan call it SimasiMac.
Symptoms
(1) Early Symptoms

No startup bongs

Irregular fine rasters, usually vertical althoughvariable

Delay of startup after power-on

Unexpected intermittent restart
(2) Terminal Symptoms

No startup

Horizontal stripes
Diagnosis and Background
On startup, Power-ON reset signals are generated endlessly.
Solutions
First of all, please try solutions (1), (2) and (3). It is easy.
(1) Check and clean connections between SIMMs (ROM-SIMM) andSIMM (ROM-SIMM) slots, and restart.
(2) Remove PDS card(s) such as an accelerator card ifinstalled, and restart.
(3) Check the battery. Replace it with a new one if voltage islow, and restart.
If nothing above works, try solutions (4), (5) or (6) AT YOUR OWNRISK. You NEED soldering and desoldering skill.
(4) Replace electrolytic capacitors C6 (1µF 50V) and C7(47µF 16V) on the logic board with new ones. Surface mount chiptype capacitors are soldered on the original logic board. But you canuse miniature radial lead type capacitors instead.
Anyway, be carefull about desoldering and soldering procedures not tobreak circuit patterns on the board. Make sure the polarity ofelectrolytic capacitors before soldering.
If you find liquid leak or corrosion of other capacitors, it is agood idea to replace them or all electrolytic capacitors with newones. Macintosh SE/30 was introduced in 1989 and discotinued in 1991.Electrolytic capacitors have been degraded after years.

(5) If solution (4) doesn't work, pull upthe sound IC chip (UB11). You can see letters 'SONY 0F09G 3430045BAPPLE85' or 'SONY 9A04 3430045B APPLE85' printed on the chip. To pullup the IC chip, connect pin 7 to pin 15 of the chip with a 1 kilo ohmresistor.
Numbering of IC Pins:
IC pins are numbered counterclockwise. Pin 1 is located at the cornermarked by a small circle or dot on the chip.


(6) If solution (5) doesn't work either, replace the networkfilter RP2 (Bourns 4120R-601-250/201).
Also see 9. BrightMonitor with neither Arrow Pointer norStartup
Replacement of chip type electrolytic capacitors solves the SimasiMacproblem in most cases.
Even if you don't have capacitor-related troubles, it's a good ideato replace them.
C1, C3, C4, C5, C7, C8, C9, C10, C12, C13: 47µF 16V
C6: 1µF 50V

2. A Bright Vertical Line in the BlackMonitor

Symptoms
When starting up Mac SE/30, only a bright vertical line is shown inthe black monitor. The width of the vertical line is approximately 5mm. During start-up, you can see moving raster patterns in thevertical line. You can hear spinning sound of the hard disk drivealso. The hard drive seems to be OK, and the vertical line seems toshow the startup picture though very compressed to 5mm in width.

Diagnosis
The horizontal sweep circuit on the analog board is broken.
Ageing and/or cracks in the soldering of either (1) P1 connector, (2)C15 electrolytic capacitor (3.9uF, 35V, 85degree C, HighFrequency,NonPolar) or (3) L2 variable inductor on the analog board is themajor cause of the problem.
The most frequent cause is soldering failure of the P1 connector dueto ageing and/or cracks. In this case, you will see the burnt and/orcharred P1 connector.
Solutions
The first thing to do is to check the connector, capacitor or theinductor, and then desolder, clean and resolder them. If the problemstill persists, replace the parts with new ones.

3. A Fine Vertical Line in the BlackMonitor

The First Thing To Do Is To Turn Off ThePower!!!!!!!!!!!
Symptoms
Mac SE/30 shows a fine vertical line in the black monitor. Inaddition, you may be able to see and/or smell smoke coming up fromthe SE/30. It's burning. Shut off the SE/30 immediately, and pull outthe power plug.

Diagnosis
The horizontal sweep circuit on the analog board is broken.
The R19 resistor (220 ohm, 1/4W, 5%) on the analog board is burntout.
Solutions
Check the R19. If it is burnt, cracked and/or charred, replace itwith a new one.

4. Herringbone Pattern Regardless ofStartup

Symptoms
When turning on the SE/30, the monitor is wavy and shows herringbonerasters.
Sometimes with startup bong and smile Mac, sometimes without startupbong nor smile Mac.

Diagnosis
One cause is a trouble of the flyback transformer on the analog boardat reference T2. The T2 flyback transformer is shielded by a metalcage, and a cable with an anode cap is attached on its top.
For SE/30, three versions of the flyback transformer were used aslisted below.
157-0042A
157-0042B
157-0042C
You can identify the version/parts number by the label attached onthe side of the flyback.
This trouble has been found most frequently in the early lots ofSE/30, in which the 157-0042A flyback was installed. The later lotsof SE/30 even with the 157-0042B or 157-0042C version also can showthe same trouble because of ageing and degradation of the flybacktransformer.
Solutions
Replace the flyback transformer with new one. Don't use 157-0042A.Use 157-0042B or 157-0042C.
Even if the flyback you can get is a used one, check its version.

5. Monitor Black Out with/withoutStartup

Symptoms
As to the symptoms when turning on the power, there are four typesincluding
(1) Black monitor with startup bong;
(2) Black monitor with startup bong and with spining sound of fan andhard disk drive;
(3) Black monitor without startup bong but with click noise; and
(4) Black monitor without startup bong and without click noise.

Diagnosis
The most probable cause of this trouble is damage of the CR2/CR3rectifiers or the Q2 transistor.
Troubles of the T2 flyback transformer sometimes results in thisproblem.
The broken CR5 rectifier also causes these symptoms, thoughrarely.
CR2 and Q2 are placed on the outer surface of the metal cage, whichshields the flyback transformer on the analog board. The cage metalaround CR2 and Q2 is locally discolored/charred, or these parts areexploded by high temperature.
If the CR3 rectifier is damaged by heat, explosion of CR3 usuallyoccurs. CR3 is placed on the inner surface of the shielding metalcage.
When CR3 is damaged but not exploded, the Q2 transistor may bedamaged simultaneously. In this case, Q2 is sometimes burnt andsometimes is not.
When Q2 is burnt out but CR3 seems to be OK, the CR5 rectifier isprobably damaged.
Even if all CR2, CR3, CR5 and Q2 appear to be OK, the inner circuitsof these parts are sometimes destroyed by heat.
Even if all these semiconductors are OK, destruction of the R22resistor also can cause Symptom(2) as described above (Black monitorwith startup bong and with spining sound...).
Solutions
Replace the broken semiconductor or resistor with new one.
CR2 and CR3 (silicon rectifying diode): GI854 (600V,3A). The muchbetter is MR824 (600V, 5A).
CR5 (silicon rectifying diode): 1N4937 (600V, 1A).
Q2 (NPN transistor): BU406 or BU406D (7A, 60W). If you cannot getBU406/BU406D, use RCA SK9085.
R22 (resistor): 470 Kohm, 1/2 W, 5%.
When the SE/30 appears totally dead (black out monitor, no startupbong, no spinning sound, no noise), the major cause of the problemsis the power supply (SONY or ASTEC). Check the power supply/powerswitch with a digital multimeter. If the power supply doesn't work,replace it with another one (new or used).

6. A Bright Horizontal Line in the BlackMonitor

Symptoms
(1) The SE/30 starts up and works normaly. After a while, the monitorsuddenly blacks out only with a bright horizontal line.
OR
(2) When turning on the SE/30, you can hear the startup bong but seeonly a bright hrizontal line in the black monitor.

Diagnosis
The vertical sweep circuit on the analog board doesn't work.
The major cause of this trouble is either of (1) connection failuredue to ageing and/or cracks in the soldering of the P1 connector, or(2) troubles of the vertical sweep IC chip at reference U2 (12-pinTV, TDA1170A) on the analog board.
Solutions
(1) The first thing to do is to check the P1 connector. If theproblem is caused by connection/soldering failure of the P1connector, you will see the burnt and/or charred P1 connector.Desolder, clean and resolder the P1 connector.
(2) If the problem still persists and the culprit is the U2 IC chip,replace it with a new TDA1170N chip.
When the U2 IC chip is broken, you may see another symptoms suchas:
(1) The screen is shrunken to the upper/lower half of the monitor andthe opposite half blacks out,
(2) The upper/lower half of the screen is extended in the verticaldirection.

7. Checker Flag Pattern

Symptoms
When turning on the power, you don't hear startup bong. The monitordisplays the checker flag pattern.

Diagnosis
(1) The most probable cause is connection troubles between theROM-SIMM and the ROM-SIMM slot.
(2) Another cause is inappropriate installation of RAM-SIMMs. Thememory size of RAM-SIMMs in Bank A is smaller than that in Bank B.You recently upgraded the memory but the configuration was wrong.
Solutions
(1) Pull out the ROM-SIMM from the ROM-SIMM slot. Clean the ROM-SIMMand the ROM-SIMM slot with volatile cleaner or ethanol. Then connectthe ROM-SIMM to the ROM-SIMM slot correctly and tightly.
(2) See 'Principles of memory upgrade for the SE/30' in the nextsection, 8. Jail Bar Pattern or Smile Mac in Jail.
When you install SIMMs of different memory size, install the largerones to Bank A and the smaller ones to Bank B. Each Bank requires aset of four SIMMs of the same memory amount.

8. Jail Bar Pattern or Smile Mac inJail

Symptoms
When you turn on the SE/30, the monitor displays vertical stripes(jail bar pattern) with/without a smile Mac. The memory was upgradedrecently. The SE/30 was completely nomal before memory upgrade.
Diagnosis
SIMMs were inserted to the wrong SIMM slots/banks.
Solutions
The working memoryconfigurations for the SE/30 are shown in the table below.
Check and re-insert the SIMMs.
Note 1
The SE/30 has eight RAM-SIMM slots on the logic board: Four slots atBank A and four slots at Bank B.
Principles of memory upgrade for the SE/30:
(1) Use 30-pin SIMMs.
(2) You need to install a set of four SIMMs of the same memory sizeto each bank.
(3) When you use only a single bank, use Bank A.
(4) When you install SIMMs of different memory size, install thelarger ones to Bank A and the smaller ones to Bank B. You also haveto remember that each Bank requires a set of four SIMMs of the samememory amount.
(5) It has been reported that some 2MB SIMMs and some 16MB SIMMsdon't work for the SE/30.
Note 2
The SE/30 has a 'dirty ROM' that can recognize only 8MB RAM, and themaximum RAM for the SE/30 is 8MB under the normal condition.
But if you install the MODE32 extension file, the SE/30 can recognizeup to 128MB RAM.
You can download theMODE32 extension file (click here) fromthe Apple download site.

9. Bright Monitor with neither Arrow Pointer norStartup

Symptoms
When turning on the power, you can see bright rasters on the monitor,but neither startup bongs nor arrow pointer comes up.

Diagnosis
The culprit is the network filter located on the logic board atreference RP2.
The model of the chip is Bourns 4120R-601-250/201, M/C 8908L 115-0002or P9120M115-0006, depending on the lot, year and/or country wherethe logic board was made.
Solutions
(1)Replace the network filter.
(2)This network filter chip, however, is hard to find/obtain atresale parts shops. If you have a skill to make it yourself, referthe circuit schematic of the filter as shown in the left figure. Itis made of sixteen 25 ohm resistors and eight 200pF capacitors.Assemble and solder them on a small IC socket, and then solder thissocket on the logic board at reference RP2.
You can download thedata sheet of Bourns 4120R-601-250/201 atthe Bourns site.

Tool For Opening A Mac Plus Crack

10. An Arrow Pointer on the Left Upper Corner butNo Smile Mac and No Startup

Symptoms
When turning on the power of the SE/30, the monitor shows the brightrasters and an arrow pointer appears on the left upper corner. Butthe monitor doesn't show a smile Mac, and the SE/30 doesn't startup.

Diagnosis
The most probable cause is a trouble of the SCSI chip on the logicboard at reference UI12.
This chip is labeled 'NCR 53C80 CP02346 609-3400257 8907N' on thetop.
Solutions
Replace the UI12 SCSI chip with new one (44-pin PLCC, 53C80-P44).

11. Monitor Out of Focus

Symptoms
The monitor of the SE/30 is out of focus. Except that, everything isOK.

Diagnosis
The variable resistor at reference R27 on the analog board is notadjusted correctly.
Solutions
Open the SE/30 and look at the vinyl jacket of the analog board. Youcan see a hole labeled Focus Control.
Adjust the focus using a hex tool (or screw driver) put into thehole.
If you cannot get the best focus only with re-adjustment of R27,replace the R26 (not R27) resistor with new one (1 Mohm, 1/2 W,5%).

12. Too Bright Monitor with Horizontal SweepLines

Symptoms
The SE/30 monitor is too bright, and you can see many horizontalsweep lines.
Even if you adjust the brightness control under the front bezel, thesymptom is not improved.

Diagnosis
There are five known causes for this symptom.
(1) The R24 variable resistor on the analog board is not adjustedcorrectly. This resistor controls the cut-off voltage.
(2) Troubles of the resistors R20 and/or R21 on the analog board.
(3) Troubles of the resistor R25 on the analog board.
(4) Troubles of the IC chip U1 on the analog board.
(5) Troubles of the transistor Q1 on the video board. The video boardis a small board where the CRT socket is soldered.
Solutions
(1) On the vinyl jacket of the analog board, you can see FocusControl, Brightness Control, Width Control and Height Control forvideo adjustments. Using the plastic hex alignment tool (screwdrivermay be OK, if you don't have the hex tool) put into the BrightnessControl hole, adjust the brightness so that the sweep lines disappearand the monitor shows the best images.
(2) If the above solution doesn't work, replace either or both of theresistors R20 (100 Kohm, 1/2 W) and R21 (1 Mohm, 1/2 W).
(3) If solutions (1) and (2) don't work, replace the resistor R25(470 Kohm, 1/4 W).
(4) If solutions (1), (2) and (3) don't work, replace the U1 IC chip(74LS38).
(5) If none of the above doesnt't work, replace the transistor Q1(2N3904, NPN transistor) on the video board.

13. A Bright Pixel at the Center of the BlackMonitor

Symptoms
When you turn on the The SE/30, you can see only a bright pixel atthe center of the black monitor.
This phenomenon appeared after disassembling and reassembling theSE/30.

Diagnosis
Both horizontal and vertical sweep circuits on the analog board don'twork.
Althogh both circuits may be broken simultaneously, this possibilityis very small.
This occurs most frequently when you disassemble and reassemble theSE/30. The most probable cause is that the yoke cable does notconnect tightly to the P1 connector on the analog board.
Solutions
Disassemble the SE/30 again, and check the connection between theyoke cable/connector and the P1 connector.

14. Wavy Display, Swaying Back and Forth of theImage

Symptoms
Normal startup and normal display. But for a short period, thedisplay is sometimes wavy, and the image is swaying back and forth(or small and large) on the display. Then, the display becomesnormal.

Diagnosis
The power supply is getting degraded and unstable with ageing. Allcomponents of the SE/30 can be affected by unstability of the powersupply. The monitor is most vulnerable, because it requires very highvoltage. This symptom, in general, indicates fluctuation of voltagefor the monitor.
Solutions
Replace the power supply.
The power supply of the SE/30 (and SE) was made by SONY and ASTEC.The SONY power supply has less trouble than the ASTEC.

Books

(1) Macintosh Repair & Upgrade Secrets.

Larry Pina, Heyden Books, 1990.

(2) The Dead Mac Scrolls.

Larry Pina, Goldstein & Blair,1992.

(3) Mac Classic & SE Repair and Upgrade Secrets.

Larry Pina, Peachpit Press, 1993.

(4) Macintosh II Repair and Upgrade Secrets.

Larry Pina, Brady Publishing, 1993.

(5) Build Your Own Macintosh and Save a Bundle., 2nd Ed.

Bob Brant, Windcrest/McGraw-Hill, 1992.

(6) Upgrading & Repairing Mac.

Lisa Lee, Hayden Books,1995.

(7) PC & Mac Handbook: Systems, Upgrades & Troubleshooting.

Steve Heath, Butterworth-Heinemann, 1996.

(8) Professional Macintosh Repair.

David Presnell, Prompt Publications, 1996.

(9) Guide to the Macintosh Family Hardware, 2nd Ed.

Addison Wesley, 1990.

(10) Troubleshooting and Repairing Computer Monitors, 2nd Ed.

Stephen J. Bigelow, McGraw-Hill, 1996.

2. Magazines

(1) OPEN DESIGN No.2, Macintosh Interface and Networking (in Japanese).

CQ Publishing, 1994.

3. CD-ROMs

Tool For Opening A Mac Plus Computer

(1) Apple Service Source v2.0 CD-ROM.

Apple, 1997.

4. Mailing Lists

(1) se30ers mailing list (in Japanese).

Maintained by Junichi Takeuchi, the president of The SE/30ers of Japan, Enthusiasts for Macintosh SE/30.

5. Forum and BBS

(1) OldMac SIG Library in the Mac Users Forum of NiftyServe (in Japanese).

6. Other Documents

(1) Other various technical documents.

Parts

• Alltech Electronics

• A & R Computing

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