Apple Lisa Troubleshooting

Troubleshooting is essential for diagnosing and resolving issues with your Apple Lisa. This guide covers the most common problems encountered with Lisa systems.

Preliminary Checks

Before detailed troubleshooting:

• Verify power outlet is working
• Check that all cables are properly connected
• Ensure the power supply voltage selector (if present) is set correctly for your region
• Discharge the power supply and verify with a meter that the primary reservoir capacitors have actually come down before touching the board. Waiting a fixed number of hours proves nothing — a supply with a failed bleed path can hold rectified mains indefinitely. The CRT needs discharging separately; see CRT Discharge Procedure

No Power / Dead System

Apple Lisa. Source: Wikimedia Commons.

No Power Diagnostics

Symptom	Possible Cause	Recommended Action
No response when power switched on	Failed mains safety capacitor	Inspect and replace the class-X capacitor across the mains input
Clicking or ticking from power supply	Power supply overload or short	Check for shorts on motherboard; replace power supply capacitors
Trips circuit breaker	Shorted mains safety capacitor	Replace the class-X capacitor. But note Apple's own table puts brightness and contrast adjustment ahead of the supply for a Lisa that trips on and off
Power supply smokes	Mains safety capacitor failure	Disconnect immediately; replace the safety capacitors
Intermittent power	Failing electrolytic capacitors	Full power supply recap recommended
Powers on briefly then shuts off	Power supply protection circuit triggering	Check for shorts; verify output voltages

The mains safety capacitor

The class-X capacitor across the mains input is the part most likely to fail dramatically in a supply of this age:

• The epoxy body absorbs moisture over decades, cracks, and fails with smoke, a bang and a

 fish-market smell

• Inspect it before first power-on after long storage; any crazing, cracking, swelling or brown

 staining means it goes now

• Replace with a modern X2-rated part of the same value. Once replaced with a current part

 it does not need doing again on any schedule

• Mains voltage and stored charge are the hazards here, not the act of opening the supply. See

 Capacitor Failure Symptoms and Recommended Tools

The specific brand fitted has not been verified for the Lisa supply and is not asserted here; the failure mode is a property of the construction, not the label.

Self-Test Error Codes

The Lisa boot ROM runs its self-test on every power-up. Apple's own account of a healthy start-up:

1. The on/off lamp lights.
2. Silence for about three seconds, then a single click.
3. About 30 seconds after power-on, as the picture tube warms, the screen shows four

 icons — CPU, I/O, Memory, Expansion — each highlighted in turn as it is tested.

1. A failing card produces error tones and its icon is drawn with a large X through

 it, and testing stops. Reseat, power up again, swap the board out if it repeats.

1. Otherwise an error icon and a numeric code appear.

Thirty seconds of blank screen is normal — Apple's flowchart only goes to the video repair procedures if there is no picture after 30 seconds. Do not chase a video fault before then.

LisaTest will not run at all unless two memory boards are fitted, in any Lisa 2 configuration. APPLE-SHIFT-S moves it from Customer Level to Service Level, where individual modules can be tested.

Apple’s start-up error codes — Appendix D, Lisa Troubleshooting Guide

Code	Apple's description	Apple's action, in order
22	Unable to clamp diskette	See the start-up error message for the "bad diskette" icon
23	Unable to read diskette	As above
25	Unable to unclamp diskette	As above
38	No boot file on diskette	As above
39	Disk controller timeout	I/O board → CPU board → motherboard
40	HMU	CPU board
41	CPU selection logic	CPU board
42	Video circuitry	CPU board
43	Parity circuitry	CPU board → memory board 1 → memory board 2 → motherboard
44	NMI error	CPU board → I/O board → motherboard
45	BUS error	I/O board → CPU board → motherboard
46	Address error	CPU board → memory board 1 → memory board 2
47	Exception	CPU board → motherboard
48	Illegal instruction	CPU board → memory board 1 → memory board 2
49	1010 or 1111 trap	CPU board → memory board 1 → memory board 2
50	COPs VIA	I/O board → CPU board → motherboard
51	Parallel port VIA	I/O board → CPU board → motherboard
52	I/O board COPs	I/O board
53	Keyboard COPs	Keyboard → I/O board → keyboard cable → motherboard
54	Clock error	I/O board
55	RS232 port A	I/O board
56	RS232 port B	I/O board
57	Disk controller	I/O board → disk drive → disk drive cables → CPU board → motherboard
58	I/O board access	I/O board → CPU board → motherboard
59	I/O board COPs code	I/O board
60	I/O or keyboard error	Keyboard → I/O board → keyboard cable → motherboard
70	Memory data	Replace the memory board named by the icon displayed
71	Memory parity	As above
75	Boot failure	See the start-up error message for the icon shown
80–85	ProFile errors	See the start-up error message for the "bad ProFile" icon
90–93	Expansion card error	See the start-up error message for the "bad expansion card" icon

Two things the old table on this page got wrong. There are no codes in the 10s and none between 60 and 70, so a banding of the form "10–19 = CPU board, 20–29 = I/O board" cannot be right: 22, 23 and 25 are diskette-handling failures and the CPU-board codes are 40–49. And 82 is not a "generic Widget failure" — Apple groups 80–85 as ProFile errors on the parallel interface, which is where the Widget also sits on a Lisa 2/10.

Code 57 (disk controller)

Apple's order is I/O board, then the drive, then the drive cables, then the CPU board, then the motherboard. Before any of that, Apple's symptom 4 in the same section says: check that the drive ribbon cable is properly secured to both the motherboard and the drive.

Codes 70 and 71 (memory)

The icon names the board. Apple: "replace the memory board specified by the icon displayed". There are no SIMMs in a Lisa — memory is on plug-in boards, Apple part 661-93105 — so clean the edge connectors and try each board on its own.

Video Problems

Display Issues

Symptom	Possible Cause	Recommended Action
No display, system runs	CRT failure or analog board issue	Check CRT connections; test analog board
Horizontal line only	Vertical deflection failure	Check vertical output IC and capacitors on analog board
Vertical line only	Horizontal deflection failure	Check horizontal output transistor and flyback
Image shifted horizontally	Horizontal phase	Apple publishes a Horizontal Phase Adjustment for this machine, in the Video Adjustments section, alongside brightness/contrast, yoke and trim-magnet adjustments
Garbled/checkered display	Memory or video RAM issue	Test with known-good memory cards
Bright flash or line at switch-off	Normal	The beam collapses as the supplies fall; it is not a fault and is not the CRT discharging itself — a switched-off Lisa is still dangerous inside until the tube is discharged deliberately. See CRT Discharge Procedure
Dim or faded display	CRT aging or brightness adjustment	Adjust brightness; CRT may need replacement

CRT adjustments

Apple's Video Adjustments section for the Lisa covers horizontal phase, brightness and contrast, yoke and magnet adjustments, with trim magnets supplied as separate colour-coded parts (159-0015 trim, 159-0020 yellow, 159-0021 red, 159-0022 green, 159-0023 blue). Apple opens the section with its own warning: "If you have never been taught how to adjust and replace the Lisa video modules do not attempt to do video repairs." The adjustments must be made with power on, so read CRT Discharge Procedure first and work to the one-hand rule.

A statement that focus is on the flyback, and that position and size controls sit on an "analog board", circulates for this machine. The Lisa's video board is Apple part 661-93107 and its flyback 076-0106; no control layout for either is documented in anything held on this wiki, so nothing specific is claimed.

Keyboard Problems

Keyboard Issues

Symptom	Possible Cause	Recommended Action
No keys working	Keyboard cable disconnected	Check cable connection to I/O board
Most keys not working	Deteriorated foam pads	Replace capacitive foam and foil pads
Some keys work, others don't	Individual pad failure	Replace foam/foil on affected keys
Keyboard error on boot	Keyboard not detected	Check cable; verify keyboard controller chip

Foam Pad Replacement

The Lisa keyboard uses capacitive foam pads that deteriorate with age:

• Purchase Lisa keyboard foam/foil replacement kit
• Each key requires a new foam pad and conductive foil
• This is the most common Lisa keyboard repair

Floppy Drive Problems

Floppy Drive Issues

Symptom	Possible Cause	Recommended Action
Drive won't accept disk	Seized eject mechanism	Clean and lubricate mechanism with isopropyl alcohol
No disk spinning	Motor or motor controller failure	Check TA7259 motor IC; may require spindle repair
Read errors	Dirty heads or alignment	Clean heads; check for alignment issues
Intermittent reads	Failing capacitors near drive controller	Check/replace associated capacitors

Floppy Emu Compatibility

• FloppyEmu can be used with Lisa systems
• Requires appropriate cable adapter
• External connection may require modification

Widget Drive Problems

The Widget (internal hard drive in Lisa 2/10) has known reliability issues:

Widget Issues

Symptom	Possible Cause	Recommended Action
Widget not recognized	Cable connection or controller failure	Check cables; verify controller on I/O board
Error 82 on boot	Generic Widget failure	Drive may need replacement with ProFile emulator
Widget spins but won't boot	Corrupted data or head issues	Attempt boot from floppy; consider drive replacement
Clicking sounds from Widget	Head or mechanism failure	Drive likely requires replacement

ProFile Emulator Options

Modern alternatives to the Widget drive:

• X/ProFile — Drop-in Widget replacement using CompactFlash
• IDEfile — ProFile emulator using IDE drives
• Both provide higher reliability than original Widget drives

The I/O-board battery pack — remove it now

The Lisa keeps its real-time clock alive with a 4 × AA NiCd pack strapped to the bottom-right of the I/O board. These packs leak corrosive electrolyte and are the single most destructive Lisa fault — when they let go they can destroy the I/O board and the motherboard, and in rare cases the CPU and RAM boards. Apple's own set-up procedure locates it precisely — "the set of four batteries on the lower right side of the I/O board" — and notes the switch next to them, which must be ON (toward the left) for the clock to keep time. A Lisa that has lost its clock may simply have that switch off, which is not a fault. For everything else: remove the battery pack from any Lisa immediately, and clean and repair any corrosion before powering up.

Board swapping

The card-based design makes diagnosis largely a matter of swapping the CPU board (661-93103), memory boards (661-93105) and I/O board (661-93104 on the Lisa 1, 661-93198 on the Lisa 2/5, 661-93171 on the Lisa 2/10), all of which Apple's own fault tables treat as field-replaceable. The CRT and video board are the parts that are not.

Power supply

A Lisa that runs for a few minutes and then switches off, or will not power on at all, has a failing power supply — a known weak point that should be serviced/recapped.

Twiggy drives (Lisa 1)

The Lisa 1 used two Apple "Twiggy" 5.25-inch drives — Apple's drive module is part 661-93110 and the capacity is usually given as 871 KB, not 860 KB — which were unreliable; most Lisa 1s were upgraded to the Lisa 2 with a Sony 400 KB 3.5-inch drive. Twiggy read errors and disk-boot failures are why so few Lisa 1s survive — a Lisa 2 conversion or a modern floppy emulator is the usual path.

Apple's own start-up error material on this wiki

Extracts from Apple's Lisa troubleshooting guide, stamped rev. 5/17/83 and footed "Page n of 51", are bound into the Service Support Training Programs binder held here and described at Service Support Tranning Programs Laserwriter Technical Procedures Jan 1985. They cover start-up repair procedures and error tones, a start-up error icon table naming the module each icon implicates, Appendix D start-up error codes, and video repair procedures — which Apple opens with the warning "If you have never been taught how to adjust…".

The extract is partial: the page footers show that only some of the 51 pages were bound in, so it will not answer every code. Where it does not, Apple Lisa Level 1 Technical Procedures Mar85 is the fuller Apple document held here.

Related Pages

• Apple Lisa
• Apple Lisa General Maintenance
• Apple Lisa Capacitor Replacement Guide
• CRT Discharge Procedure