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Apple LaserWriter II SC: Difference between revisions

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{{Infobox computer peripheral
{{Infobox computer peripheral
| name        = Apple LaserWriter II SC
| name        = Apple LaserWriter II SC
| image        = [[File:Apple_LaserWriter_II.jpg|250px]]
| image        = [[File:Apple LaserWriter II (All About Apple museum).jpg|260px|frameless]]
| caption      = Apple LaserWriter II
| caption      = Apple LaserWriter II (the SC, NT and NTX share this case)
| manufacturer = Apple Computer, Inc.
| manufacturer = Apple Computer, Inc.
| type        = Laser printer
| type        = Laser printer
| interface    = SCSI; Apple Desktop Bus connector present
| interface    = SCSI; Apple Desktop Bus connector present
| compatible  = Macintosh with SCSI
| compatible  = Macintosh with SCSI
| dimensions  = 8.6 in. H x 20 in. W x 18.5 in. D
| dimensions  = 8.6 in high × 20 in wide × 18.5 in deep
| weight      = 45 lb (20.25 kg)
| weight      = 45 lb (20.25 kg)
| power        = 90-126 V AC, 50-60 Hz
| power        = 90-126 V AC, 50-60 Hz
}}
}}
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<templatestyles src="Template:StyledTable/styles.css" />
The '''Apple LaserWriter II SC''' is the entry-level member of the LaserWriter II range. It has '''no PostScript interpreter and no LocalTalk''': the host Macintosh renders the page with QuickDraw and the printer receives and prints the result over '''SCSI'''.<ref name="asg">''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]] ([[:File:Apple LaserWriter Printers Volume I.pdf|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.</ref> It shares the '''Canon LBP-SX''' engine, the case, the power supply and the entire mechanical parts list with the rest of the range.
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.<ref name="asg">''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]] ([[:File:Apple LaserWriter Printers Volume I.pdf|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.</ref> 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.<ref name="asg" />
 
Its controller-I/O board is the least capable Apple fitted: a '''68000 at 7.45 MHz''', '''16 KB of ROM''' and '''1.0 MB of RAM'''.<ref name="asg" />
 
'''It does have built-in fonts.''' Apple's specification table lists '''Times, Helvetica, Courier and Symbol''' for the SC.<ref name="asg" /> Statements that the SC has no fonts at all are wrong.


== SCSI ==
== 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.<ref name="asg" />
The SC is the only LaserWriter with SCSI as its sole interface. The rear panel carries an '''Apple Desktop Bus connector''', a '''SCSI''' connector and a '''SCSI ID switch'''.<ref name="asg" />
 
The ADB connector is present on the SC, NT and NTX and was '''removed on the IIf and IIg''', which use a pushbutton switch instead.<ref name="asg" /> Apple's guide documents its presence but describes no function for it, so none is claimed here.


{| class="wikitable styled-table" style="width:80%;"
{| class="wikitable styled-table" style="width:80%;"
|+'''SCSI port — BR-50 male''' (shared with the NTX, IIf, IIg and Personal LaserWriter SC)<ref name="asg" />
|+'''SCSI port, BR-50 (as on the NTX, IIf, IIg and Personal LaserWriter SC)'''
! Pins !! Signal
! Pins !! Signal
|-
|-
| 1–12, 14–25, 35–37, 39, 40, 42 || Signal ground
| 1-12, 14-25, 35-37, 39, 40, 42 || Signal ground
|-
|-
| 13 || No connection
| 13 || No connection
|-
|-
| 26–33 || Data bits 0–7
| 26-33 || Data bits 0-7
|-
|-
| 34 || Data parity
| 34 || Data parity
|-
|-
| 38 || '''+5 V'''
| 38 || +5 V
|-
|-
| 41 || ATN/ (Attention)
| 41 || ATN/ (attention)
|-
|-
| 43 || BSY/ (Busy)
| 43 || BSY/ (busy)
|-
|-
| 44 || ACK/ (Acknowledge)
| 44 || ACK/ (acknowledge)
|-
|-
| 45 || RST/ (Reset)
| 45 || RST/ (reset)
|-
|-
| 46 || MSG/ (Message)
| 46 || MSG/ (message)
|-
|-
| 47 || SEL/ (Select)
| 47 || SEL/ (select)
|-
|-
| 48 || C/D/ (Control/Data)
| 48 || C/D/ (control/data)
|-
|-
| 49 || REQ/ (Request)
| 49 || REQ/ (request)
|-
|-
| 50 || I/O/ (Input/Output)
| 50 || I/O/ (input/output)
|}
|}
<ref name="asg" />


Apple's cable list for the SC:<ref name="asg" /> SCSI System Cable, service part 658-8031 or 590-0305, Apple model '''M0206''', BR-50 to DB-25 male-to-male; SCSI Terminator '''M0209''' (658-8032 / 590-0304), BR-50 male to female; SCSI Cable Extender '''M0208''' (658-8033 / 590-0307); SCSI Peripheral Cable '''M0207''' (658-8034 / 590-0306), BR-50 male to male.
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).<ref name="asg" />


== The Two Test Pages ==
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.<ref name="gmfh-scsi">''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.</ref>


This is the most useful pair of facts on the page, because between them they split the machine in half.<ref name="asg" />
== 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.<ref name="asg" />


=== Engine self-test page ===
The SC prints its startup test page, which confirms the SC controller-I/O board, whenever its SCSI ID switch is set to 7.<ref name="asg" /> Because the Macintosh itself is always SCSI ID 7, set the printer back to its own unique ID after the test.<ref name="gmfh-scsi" />
'''Press the engine self-test switch on the side of the printer, behind the access cover.'''<ref name="asg" /> This runs the '''print engine alone'''. No computer, no SCSI, no driver.


=== SC startup test page ===
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.<ref name="asg" /><ref name="gmfh-scsi" />
'''Set the SCSI ID number to "7."'''<ref name="asg" /> The SC then generates a startup test page at power-on, confirming the '''SC controller-I/O board'''.
 
So: a fault on the engine self-test page is in the engine. A machine that prints a clean engine self-test but fails the SCSI ID 7 startup page has a controller-I/O board fault. A machine that passes both but will not print from the Macintosh has a SCSI, cable, driver or host problem.
 
'''Note that SCSI ID 7 is a diagnostic mode, not a normal setting.''' Leaving the ID at 7 will also collide with the host adapter on a Macintosh SCSI bus.
 
== SCSI Troubleshooting ==
 
Before suspecting the printer:
 
* '''Set a unique SCSI ID''' in the range the machine allows, and not 7.<ref name="asg" />
* Check '''termination''' — the printer must be terminated if it is at the end of the chain, and Apple sells a specific terminator, model M0209.<ref name="asg" />
* Test with the printer as the '''only''' SCSI device.
* Use Apple's cables. The connector is '''BR-50''' at the printer end, not the DB-25 used at the Macintosh end.<ref name="asg" />


== Specifications ==
== Specifications ==
Apple's controller-I/O board table for the whole LaserWriter II range, which is the clearest single comparison available:<ref name="asg" />
{| class="wikitable styled-table" style="width:95%;"
{| class="wikitable styled-table" style="width:95%;"
|+'''Controller-I/O board specifications'''<ref name="asg" />
|+'''Controller-I/O board specifications, LaserWriter II range'''
! !! SC !! NT !! NTX !! IIf !! IIg
! !! 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)
| 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
| 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
| 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
| 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 & 2, HP LaserJet IIP || PostScript Level 1 & 2, HP LaserJet IIP
| 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
| 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
|}
|}
 
<ref name="asg" />
Two entries there are widely misreported. '''The IIf runs at 20.0 MHz''', not 25.0 — the IIg is the 25 MHz machine. And '''the SC does have built-in fonts''': Times, Helvetica, Courier and Symbol. Claims that it has none are wrong by Apple's own table.


{| class="wikitable styled-table" style="width:90%;"
{| class="wikitable styled-table" style="width:90%;"
|+'''LaserWriter II print engine specifications'''<ref name="asg" />
|+'''LaserWriter II print engine specifications'''
| '''Marking engine''' || Canon LBP-SX laser xerographic
| Marking engine || Canon LBP-SX laser xerographic
|-
|-
| '''Print resolution''' || 300 dots per inch
| Print resolution || 300 dots per inch
|-
|-
| '''Speed''' || 8 pages per minute
| Speed || 8 pages per minute
|-
|-
| '''Print materials''' || Letter, legal, A4 and B5 sizes use '''16–20 lb''' single-sheet photocopy bond, '''8–34 lb''' letterhead and coloured stock, or transparency overhead film. Envelopes, labels and paper up to '''36 lb''' via manual feed; envelopes also via an optional envelope tray
| 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. Envelope cassette holds 15 envelopes'''
| 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.
| Printable surface || Letter 8.0 &times; 10.5 in; Legal 8.0 &times; 13.0 in; A4 7.41 &times; 10.86 in; B5 7.69 &times; 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)'''
| 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%
| Operating environment || 50 to 90&nbsp;&deg;F (10 to 32.5&nbsp;&deg;C); humidity 20% to 80%
|-
|-
| '''Power requirements''' || '''90 to 126 volts AC; 50 to 60 Hz'''
| Power requirements || 90 to 126 V AC; 50 to 60 Hz
|}
|}
 
<ref name="asg" />
'''The cassette holds 200 sheets, not 250.''' Apple's guide gives no wattage, current or BTU figure for the LaserWriter II, and none is stated here.


== Safety ==
== Safety ==
 
The LaserWriter family safety rules apply:<ref name="asg" />
The LaserWriter family safety rules apply in full:<ref name="asg" />
* 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.
* '''High voltage.''' Switch off and disconnect the AC power cord before servicing. Certain parts are electrified under power. Never work on the printer under power '''except when making live adjustments'''.
* The fuser rollers become very hot. Switch off for at least five minutes before servicing them.
* '''Laser.''' '''Do not disconnect the optical fibre cable when the printer is powered on.''' The fibre carries the infrared laser beam, '''which you cannot see but which can permanently damage your eyes'''. When servicing the optical system, do not put screwdrivers or other shiny objects in the beam path — the reflected beam is equally dangerous.
* Do not be grounded when working on plugged-in equipment or making live adjustments, and remove all jewellery first.
* '''Fuser.''' The fuser rollers become very hot. '''Switch off for at least five minutes''' before servicing them.
* The controller-I/O board contains CMOS parts; handle chips, ROMs and SIMMs by their edges.
* '''Do not touch''', with covers off and power on: the high-voltage power supply, the DC power supply, or '''the power supply block''' (which is the LaserWriter II-specific item on Apple's list).
* 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.
* '''Do not be grounded''' when working on plugged-in equipment or making live adjustments, and '''remove all jewellery before you start'''.
* Never use an ammonia-based cleaner on the LaserWriter II; it discolours the plastic.
* '''ESD.''' The controller-I/O board contains CMOS parts, and CMOS chips, ROMs and SIMMs are very susceptible to electrostatic discharge and skin acid. '''Handle them by the edges only.'''
* '''Toner''' is non-toxic — plastic, iron and a little pigment. Remove as much as possible with a dry tissue, then wash with '''cold''' water; hot water gels it and fuses it permanently into fabric. '''Toner attacks vinyl.'''
* '''Never use an ammonia-based cleaner on the LaserWriter II''' — it discolours the plastic.


== Status LEDs ==
== Status LEDs ==
'''There are four, all on the front panel, and none of them is a "Service" light.'''<ref name="asg" />
{| class="wikitable styled-table" style="width:92%;"
{| class="wikitable styled-table" style="width:92%;"
|+'''LaserWriter II status LEDs'''<ref name="asg" />
|+'''LaserWriter II status LEDs'''
! LED !! Colour !! Behaviour
! LED !! Colour !! Behaviour
|-
|-
| '''Ready''' || Green || Flashes during warm-up and while the printer is operating. Steady when warmed up and ready. '''Off''' when the printer is not ready, an error condition exists, or the top cover is open
| 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''' || On and steady when the toner cartridge needs replacement. '''Flashes when the cartridge is installed incorrectly'''
| Low-Toner || Orange || Steady when the toner cartridge needs replacing; flashes when the cartridge is installed incorrectly
|-
|-
| '''Paper-Out''' || '''Red''' || On and steady when out of paper or the paper tray is missing. '''Flashes when the printer is ready to accept manually fed paper'''
| 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 || Comes on when paper jams and stays on until the jam is cleared
| Paper Jam || Red || On when paper jams, until the jam is cleared
|}
|}
<ref name="asg" />


'''The error indication is a combination, not a light of its own:'''<ref name="asg" />
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.<ref name="asg" />
 
> When both the red '''Paper-Out''' and '''Paper Jam''' lights flash, the controller-I/O board or the print engine has an error condition.
 
Three of the four behaviours above are easy to misread as faults when they are not: the Ready light being '''off''' is how the printer reports trouble; a '''flashing''' Low-Toner light means the cartridge is seated wrongly, not empty; and a '''flashing''' Paper-Out light means the printer is waiting for you to hand-feed a sheet.
 
== Test Pages ==
 
Three different pages, testing different parts of the machine.<ref name="asg" />
 
=== Engine self-test page — tests the print engine ===
'''Press the engine self-test switch, located on the side of the printer behind the access cover.'''<ref name="asg" /> This confirms the print engine and is how you isolate engine failures from controller-I/O board failures. It is the single most valuable diagnostic on the machine and it needs no computer attached.
 
=== SC startup test page ===
'''The LaserWriter II SC generates a startup test page whenever the SCSI ID number is set to "7."'''<ref name="asg" /> This confirms the SC controller-I/O board.
 
=== NT, NTX, IIf and IIg startup test pages ===
These models generate a startup test page '''every time they are switched on''', unless switched off with PostScript software or the LaserWriter Utility program.<ref name="asg" /> It confirms the controller-I/O board and carries the page count.
 
'''The diagnostic question this sets up is the one to ask first:''' does the fault appear on an engine self-test page? If yes, it is in the engine. If it appears only when printing from a computer, it is in the controller-I/O board, the cable or the host.


== Troubleshooting ==
== Troubleshooting ==
=== Pre-power-on checklist ===
=== Pre-power-on checklist ===
Apple's list, to be checked before the flowcharts:<ref name="asg" />
Apple's list, to work through before the flowcharts:<ref name="asg" />
 
* Line voltage 115 V AC &plusmn;10%
* Line voltage is OK — '''115 volts AC ±10%'''
* Printer on a solid, level surface
* Printer is on a solid, level surface
* Room temperature 50-90&nbsp;&deg;F (10-32.5&nbsp;&deg;C), humidity 20% to 80%
* Room temperature '''50–90 °F (10–32.5 °C)''', humidity 20%–80%
* Not in a hot, humid or dusty place or near open flames
* Not in a hot, humid or dusty area, nor near open flames
* Printer not exposed to ammonia gas
* '''Printer is not exposed to ammonia gas'''
* Out of direct sunlight and well ventilated
* Not in direct sunlight; well ventilated
* Cables and connectors OK
* Cables and connectors are OK
* Toner cartridge installed and containing toner
* Toner cartridge installed and has toner
* Fuser roller cleaner felt in place and not dirty
* '''Fuser roller cleaner felt is in place and not dirty'''
* Print density dial set correctly
* Print density adjustment dial set correctly
* Paper cassette properly loaded and paper within specification
* Paper cassette properly loaded and paper within specification
* '''Transfer corona wire clean and unbroken'''
* Transfer corona wire clean and unbroken
* '''I/O PCA DIP switches are set correctly'''
* I/O PCA DIP switches set correctly


=== Troubleshooting order ===
=== Troubleshooting order ===
Apple's sequence is fixed: check the pre-power-on list; be familiar with the safety section before any live electrical check; for an SC or NT/NTX begin with '''Troubleshooting Flowchart 1''' and proceed function by function; '''if you replace a module and the problem remains, reinstall the original before proceeding'''; and perform preventive maintenance before returning the printer.<ref name="asg" />
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.<ref name="asg" /> The status-LED diagnostic with the rotary switch and the LaserWriter II Test Connector applies only to the IIf and IIg.<ref name="asg" />
 
=== The IIf/IIg status-LED diagnostic ===
Not applicable to this model, but worth knowing exists: on a IIf or IIg you set the rear rotary switch to '''4''', connect the '''LaserWriter II Test Connector''' to the DB-25 serial port, switch on and read the four status LEDs against a table that names the failed part — fuser, laser, scanner, controller-I/O board, or a specific ROM or SIMM position.<ref name="asg" />
 
== Preventive Maintenance ==
 
=== Before starting ===
Power off and unplug; '''let the fuser rollers cool'''; prepare for ESD; spread a drop cloth against grease and spilled toner.<ref name="asg" />


=== Page count ===
== Preventive maintenance ==
The startup test page gives the pages printed '''since the controller-I/O board was installed''' — accurate only if that board has never been replaced or upgraded. If it has, Apple's instruction is to check the '''Repair Log Label affixed to the bottom of the printer''' and ask the customer.<ref name="asg" />
Before starting, switch off and unplug, let the fuser rollers cool, take ESD precautions and lay a drop cloth against grease and toner.<ref name="asg" />


=== Apple's parts replacement schedule ===
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.<ref name="asg" />
'''Every 50,000 prints:''' replace the '''ozone filter''' and check the fan.<ref name="asg" />


'''Every 100,000 prints,''' replace:<ref name="asg" />
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.<ref name="asg" />
* Fuser assembly
* Transfer guide assembly
* Preconditioning exposure assembly
* Paper feed roller assembly
* Transfer corona assembly


=== Cleaning ===
{| class="wikitable styled-table" style="width:80%;"
{| class="wikitable styled-table" style="width:80%;"
|+'''Service points and what to use'''<ref name="asg" />
|+'''Service points and cleaning materials'''
! Service point !! Tool or solvent
! Service point !! Tool or solvent
|-
|-
Line 247: Line 181:
| Registration rollers || Cloth dampened with water
| Registration rollers || Cloth dampened with water
|}
|}
<ref name="asg" />


Apple splits these into items the customer cleans as needed (the first five) and a dealer list to be done '''every 12 months or at each service call''' (all ten).<ref name="asg" /> Note which points take water and which take alcohol — they are not interchangeable.
The customer cleans the first five items as needed; the dealer cleans all ten every 12 months or at each service call.<ref name="asg" />


== Parts ==
== Parts ==
Selected entries common to the LaserWriter II range:<ref name="asg" />
Selected entries common to the LaserWriter II range:<ref name="asg" />


Line 257: Line 191:
! Part !! Number
! Part !! Number
|-
|-
| DC Controller PCA || 661-0426
| DC controller PCA || 661-0426
|-
|-
| DC Power Supply, 110/115 V || 661-0424
| DC power supply, 110/115 V || 661-0424
|-
|-
| DC Power Supply, 220/240 V || 661-0442
| DC power supply, 220/240 V || 661-0442
|-
|-
| Fuse, 125 V 6.3 A || 941-0005
| Fuse, 125 V 6.3 A || 941-0005
Line 267: Line 201:
| Fuse, medium time lag 3.15 A, 250 V || 740-0061
| Fuse, medium time lag 3.15 A, 250 V || 740-0061
|-
|-
| High-Voltage Power Supply || 661-0425
| High-voltage power supply || 661-0425
|-
|-
| Laser/Scanner Assembly || 661-0423
| Laser/scanner assembly || 661-0423
|-
|-
| '''Fuser Assembly, 110/115 V''' || 661-0440
| Fuser assembly, 110/115 V || 661-0440
|-
|-
| '''Fuser Assembly, 220/240 V''' || 661-0444
| Fuser assembly, 220/240 V || 661-0444
|-
|-
| Fuser Heater, 100 V, '''620 W''' || 938-0003
| Fuser heater, 100 V, 620 W || 938-0003
|-
|-
| Fuser Heater, 220 V, '''570 W''' || 938-0004
| Fuser heater, 220 V, 570 W || 938-0004
|-
|-
| Fuser Roller Cleaner || 970-0049
| Fuser roller cleaner || 970-0049
|-
|-
| '''Ozone Filter''' || 961-0003
| Ozone filter || 961-0003
|-
|-
| Ozone Filter (for case with door) || 961-0007
| Ozone filter (for case with door) || 961-0007
|-
|-
| Power Supply Block, 110/115 V || 661-0427
| Power supply block, 110/115 V || 661-0427
|-
|-
| Power Supply Block, 220/240 V || 661-0443
| Power supply block, 220/240 V || 661-0443
|-
|-
| Transfer Corona Assembly || 971-0026
| Transfer corona assembly || 971-0026
|-
|-
| Transfer Guide Assembly || 971-0019
| Transfer guide assembly || 971-0019
|-
|-
| Paper Feed Roller Assembly || 971-0017
| Paper feed roller assembly || 971-0017
|-
|-
| Fan, Lower || 959-0021
| Fan, lower || 959-0021
|-
|-
| Fan, Upper || 959-0022
| Fan, upper || 959-0022
|-
|-
| Cleaning Brush || 970-0047
| Cleaning brush || 970-0047
|-
|-
| Mirror Assembly || 971-0007
| 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'''.<ref name="asg" /> The fuser heaters differ in wattage as well as voltage — 620 W at 100 V, 570 W at 220 V.
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.<ref name="asg" />


== Service manuals ==
<pdf>File:Apple LaserWriter Printers Volume I.pdf</pdf>


== Service Manual ==
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]].
<pdf>File:Apple LaserWriter Printers Volume I.pdf</pdf>


== See Also ==
== Related pages ==
* [[Apple LaserWriter II General Maintenance]]
* [[Apple LaserWriter II Troubleshooting Guide]]
* [[Apple LaserWriter II NTX]], [[Apple LaserWriter IIf]], [[Apple LaserWriter IIg]]
* [[Apple LaserWriter II NT]]
* [[Apple LaserWriter II NT]]
* [[Apple LaserWriter]]
* [[Apple LaserWriter]]
Line 316: Line 254:


== References ==
== References ==
<references />
<references />



Latest revision as of 11:48, 2 October 2026

Apple LaserWriter II SC
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]

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]

SCSI port, BR-50 (as on the NTX, IIf, IIg and Personal LaserWriter SC)
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)

[1]

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

[edit | edit source]

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

[edit | edit source]
Controller-I/O board specifications, LaserWriter II range
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

[1]

LaserWriter II print engine specifications
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

[1]

Safety

[edit | edit source]

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

[edit | edit source]
LaserWriter II 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

[1]

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

[edit | edit source]

Pre-power-on checklist

[edit | edit source]

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

[edit | edit source]

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

[edit | edit source]

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 points and cleaning materials
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

[1]

The customer cleans the first five items as needed; the dealer cleans all ten every 12 months or at each service call.[1]

Parts

[edit | edit source]

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

[edit | edit source]

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.

[edit | edit source]

References

[edit | edit source]
  1. ↑ 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. ↑ 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.