Apple LaserWriter II SC
| Apple LaserWriter II SC | |
|---|---|
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|
| Apple LaserWriter II (the SC, NT and NTX share this case) | |
| Manufacturer | Apple Computer, Inc. |
| Type | Laser printer |
| Interface | SCSI; Apple Desktop Bus connector present |
| Compatible | Macintosh with SCSI |
| Dimensions | 8.6 in high × 20 in wide × 18.5 in deep |
| Weight | 45 lb (20.25 kg) |
| Power | 90-126 V AC, 50-60 Hz |
The Apple LaserWriter II SC is the entry-level member of the LaserWriter II range. Its imaging language is QuickDraw rather than PostScript, and its only interface is SCSI.[1] It shares the Canon LBP-SX engine, the case, the power supply and the mechanical parts with the rest of the range. Its controller-I/O board has a 68000 at 7.45 MHz, 16 KB of ROM and 1.0 MB of RAM, and Apple lists Times, Helvetica, Courier and Symbol as its built-in fonts.[1]
SCSI
The rear panel carries an Apple Desktop Bus connector, a SCSI connector and a SCSI ID switch. The SC, NT and NTX have the ADB connector; the IIf and IIg do not, and use a pushbutton switch instead. Apple's guide shows the connector but describes no function for it.[1]
| Pins | Signal |
|---|---|
| 1-12, 14-25, 35-37, 39, 40, 42 | Signal ground |
| 13 | No connection |
| 26-33 | Data bits 0-7 |
| 34 | Data parity |
| 38 | +5 V |
| 41 | ATN/ (attention) |
| 43 | BSY/ (busy) |
| 44 | ACK/ (acknowledge) |
| 45 | RST/ (reset) |
| 46 | MSG/ (message) |
| 47 | SEL/ (select) |
| 48 | C/D/ (control/data) |
| 49 | REQ/ (request) |
| 50 | I/O/ (input/output) |
Apple's cables for the SC are the SCSI System Cable (service part 658-8031 or 590-0305, model M0206, BR-50 to DB-25, male to male), the SCSI Terminator (M0209, 658-8032 or 590-0304, BR-50 male to female), the SCSI Cable Extender (M0208, 658-8033 or 590-0307) and the SCSI Peripheral Cable (M0207, 658-8034 or 590-0306, BR-50 male to male).[1]
On a Macintosh SCSI bus each device needs a unique ID from 0 to 7; the Macintosh is always 7 and an internal SCSI device is always 0. At least one set of termination resistors is needed when external devices are connected, a chain with several devices or more than about 3 feet of cable may need a set at each end, and there must never be more than two sets on the bus.[2]
Test pages
The engine self-test page checks the print engine alone. Press the engine self-test switch on the side of the printer, behind the access cover; no computer or SCSI connection is involved.[1]
The SC prints its startup test page, which confirms the SC controller-I/O board, whenever its SCSI ID switch is set to 7.[1] Because the Macintosh itself is always SCSI ID 7, set the printer back to its own unique ID after the test.[2]
A fault on the engine self-test page is in the engine. A printer that gives a clean self-test page but no startup page at ID 7 points to the controller-I/O board; one that passes both but will not print from the Macintosh points to the SCSI ID, termination, cable, driver or host.[1][2]
Specifications
| SC | NT | NTX | IIf | IIg | |
|---|---|---|---|---|---|
| CPU | 68000 (7.45 MHz) | 68000 (11.16 MHz) | 68020 (16.67 MHz) | 68030 (20.0 MHz) | 68030 (25.0 MHz) |
| ROM | 16 KB | 1.0 MB | 1.0 MB | 2.0 MB | 2.0 MB |
| RAM | 1.0 MB | 2.0 MB | 2.0 MB, expandable to 12 MB | 2.0 MB, expandable to 32 MB | 5.0 MB, expandable to 32 MB |
| I/O | SCSI | LocalTalk, RS-232, RS-422 | LocalTalk, RS-232, RS-422, SCSI | LocalTalk, RS-232, RS-422, SCSI | LocalTalk, RS-232, RS-422, SCSI, Ethernet |
| Imaging language | QuickDraw | PostScript, Diablo 630 | PostScript, Diablo 630, HP LaserJet | PostScript Level 1 and 2, HP LaserJet IIP | PostScript Level 1 and 2, HP LaserJet IIP |
| Built-in fonts | Times, Helvetica, Courier, Symbol | Times, Courier, Symbol, Palatino, Helvetica, Helvetica Narrow, ITC Bookman, ITC Avant Garde, ITC Zapf Chancery, New Century Schoolbook, ITC Zapf Dingbats | As NT | As NT | As NT |
| Marking engine | Canon LBP-SX laser xerographic |
| Print resolution | 300 dots per inch |
| Speed | 8 pages per minute |
| Print materials | Letter, legal, A4 and B5 in 16-20 lb single-sheet photocopy bond, 8-34 lb letterhead and coloured stock, or overhead transparency film. Envelopes, labels and paper up to 36 lb by manual feed; envelopes also from an optional envelope tray |
| Print capacities | Paper cassettes hold 200 sheets of 20 lb paper; the envelope cassette holds 15 envelopes |
| Printable surface | Letter 8.0 × 10.5 in; Legal 8.0 × 13.0 in; A4 7.41 × 10.86 in; B5 7.69 × 10.16 in |
| Physical dimensions | Height 8.6 in (21.8 cm); width 20 in (50.8 cm); depth 18.5 in (47 cm); weight 45 lb (20.25 kg) |
| Operating environment | 50 to 90 °F (10 to 32.5 °C); humidity 20% to 80% |
| Power requirements | 90 to 126 V AC; 50 to 60 Hz |
Safety
The LaserWriter family safety rules apply:[1]
- Switch off and disconnect the power cord before servicing. Parts are live under power; never work on the printer under power except when making live adjustments. With the covers off and the power on, do not touch the high-voltage power supply, the DC power supply or the power supply block.
- Do not disconnect the optical fibre cable with the printer on. It carries the infrared laser beam, which cannot be seen and can permanently damage the eyes. Keep screwdrivers and other shiny objects out of the beam path; the reflection is equally dangerous.
- The fuser rollers become very hot. Switch off for at least five minutes before servicing them.
- Do not be grounded when working on plugged-in equipment or making live adjustments, and remove all jewellery first.
- The controller-I/O board contains CMOS parts; handle chips, ROMs and SIMMs by their edges.
- Toner is non-toxic (plastic, iron and a little pigment). Remove it with a dry tissue and wash with cold water; hot water makes it gel and fuse into fabric. Toner attacks vinyl.
- Never use an ammonia-based cleaner on the LaserWriter II; it discolours the plastic.
Status LEDs
| LED | Colour | Behaviour |
|---|---|---|
| Ready | Green | Flashes during warm-up and while printing; steady when ready; off when the printer is not ready, an error exists or the top cover is open |
| Low-Toner | Orange | Steady when the toner cartridge needs replacing; flashes when the cartridge is installed incorrectly |
| Paper-Out | Red | Steady when out of paper or the paper tray is missing; flashes when the printer is ready for a manually fed sheet |
| Paper Jam | Red | On when paper jams, until the jam is cleared |
When the Paper-Out and Paper Jam lights flash together, the controller-I/O board or the print engine has an error condition. A flashing Low-Toner light means the cartridge is seated wrongly, and a flashing Paper-Out light means the printer is waiting for a hand-fed sheet.[1]
Troubleshooting
Pre-power-on checklist
Apple's list, to work through before the flowcharts:[1]
- Line voltage 115 V AC ±10%
- Printer on a solid, level surface
- Room temperature 50-90 °F (10-32.5 °C), humidity 20% to 80%
- Not in a hot, humid or dusty place or near open flames
- Printer not exposed to ammonia gas
- Out of direct sunlight and well ventilated
- Cables and connectors OK
- Toner cartridge installed and containing toner
- Fuser roller cleaner felt in place and not dirty
- Print density dial set correctly
- Paper cassette properly loaded and paper within specification
- Transfer corona wire clean and unbroken
- I/O PCA DIP switches set correctly
Troubleshooting order
Apple's sequence is: work through the pre-power-on list; read the safety section before any live electrical check; for an SC or NT/NTX, start with Troubleshooting Flowchart 1 and continue function by function; if a replacement module does not cure the fault, refit the original before going on; and carry out preventive maintenance before returning the printer.[1] The status-LED diagnostic with the rotary switch and the LaserWriter II Test Connector applies only to the IIf and IIg.[1]
Preventive maintenance
Before starting, switch off and unplug, let the fuser rollers cool, take ESD precautions and lay a drop cloth against grease and toner.[1]
The startup test page shows the pages printed since the controller-I/O board was installed. If the board has been replaced or upgraded, Apple's instruction is to check the Repair Log Label on the bottom of the printer and ask the customer.[1]
Every 50,000 prints, replace the ozone filter and check the fan. Every 100,000 prints, replace the fuser assembly, the transfer guide assembly, the preconditioning exposure assembly, the paper feed roller assembly and the transfer corona assembly.[1]
| Service point | Tool or solvent |
|---|---|
| Primary corona wire | Cleaning brush supplied with the printer |
| Transfer corona wire | Cotton swab (with isopropyl alcohol, for user cleaning) |
| Transfer guide | Cloth dampened with water |
| Fuser rollers | Fuser cleaning pad |
| Exterior case | Cloth dampened with water |
| Separation claws | Cloth dampened with alcohol |
| Paper guide | Cloth dampened with alcohol |
| Lower delivery guide | Cloth dampened with alcohol |
| Feeder guide | Cloth dampened with water |
| Registration rollers | Cloth dampened with water |
The customer cleans the first five items as needed; the dealer cleans all ten every 12 months or at each service call.[1]
Parts
Selected entries common to the LaserWriter II range:[1]
| Part | Number |
|---|---|
| DC controller PCA | 661-0426 |
| DC power supply, 110/115 V | 661-0424 |
| DC power supply, 220/240 V | 661-0442 |
| Fuse, 125 V 6.3 A | 941-0005 |
| Fuse, medium time lag 3.15 A, 250 V | 740-0061 |
| High-voltage power supply | 661-0425 |
| Laser/scanner assembly | 661-0423 |
| Fuser assembly, 110/115 V | 661-0440 |
| Fuser assembly, 220/240 V | 661-0444 |
| Fuser heater, 100 V, 620 W | 938-0003 |
| Fuser heater, 220 V, 570 W | 938-0004 |
| Fuser roller cleaner | 970-0049 |
| Ozone filter | 961-0003 |
| Ozone filter (for case with door) | 961-0007 |
| Power supply block, 110/115 V | 661-0427 |
| Power supply block, 220/240 V | 661-0443 |
| Transfer corona assembly | 971-0026 |
| Transfer guide assembly | 971-0019 |
| Paper feed roller assembly | 971-0017 |
| Fan, lower | 959-0021 |
| Fan, upper | 959-0022 |
| Cleaning brush | 970-0047 |
| Mirror assembly | 971-0007 |
The DC power supply, fuser assembly, fuser heater and power supply block are different parts for 110 V and 220 V machines, and the two fuser heaters are rated 620 W at 100 V and 570 W at 220 V.[1]
Service manuals
The LaserWriter II service course (File:Apple LaserWriter II Service Training Participant Manual Version 1.1 Oct 1992.pdf) covers the SC, NT and NTX I/O boards and the engine subsystems; see Apple LaserWriter II NT.
Related pages
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 Apple Service Guide for LaserWriter Printers, Volume I, Apple Computer, Inc., January 1992 (072-0631-B), hosted on this wiki as Apple LaserWriter Printers Volume I (PDF). Covers the LaserWriter, LaserWriter Plus, LaserWriter II SC/NT/NTX/IIf/IIg and Personal LaserWriter SC/NT/LS. Introductory safety section: the high-voltage, optical-fibre, fuser-cooling, ESD, not-being-grounded and lifting warnings; the LaserWriter Safety Rules; the toner-safety paragraph; the laser-safety paragraph and the three laser warning labels. Tab 2, LaserWriter/LaserWriter Plus: parts list with part numbers (pages 3-4); print engine specifications (page 7); status lights (page 8); service test print and user test print (page 9); the pre-power-on checklist and troubleshooting flowcharts and tables (pages 10-51); the LaserWriter Plus ROM upgrade (pages 52-53); the laser power adjustment (page 54); the image skew adjustment (pages 55-56); and preventive maintenance including the page counter, the maintenance schedule and the Standard Maintenance and 100,000-Page Service checkpoint tables (pages 57-60). Tab 3, LaserWriter II: parts list (pages 4-5); controller-I/O board specifications (page 10); print engine specifications (page 11); status LEDs (page 12); test pages (page 13); the pre-power-on checklist, the IIf/IIg status-LED diagnostic chart and the troubleshooting tables (pages 14-54); the laser power output check (page 55); the NTX memory and ROM upgrades (pages 56-57); the IIf/IIg memory upgrade (page 58); and preventive maintenance (pages 59-60). Tab 6, Ports and Cables: the peripheral cable table, external connector diagrams, connector pin-outs and switch configurations.
- ↑ 2.0 2.1 2.2 Guide to the Macintosh Family Hardware, second edition, Apple Computer, Inc. / Addison-Wesley, 1990, hosted as File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf. Chapter 11, "SCSI Ports", pp. 376-377: device IDs (the Macintosh always 7, an internal device always 0) and termination rules.