Apple Personal LaserWriter 300

Apple Personal LaserWriter 300
Apple Personal LaserWriter 300
Manufacturer	Apple Computer, Inc.
Type	Laser printer
Release date	1 June 1993
Interface	RS-422 serial (mini-DIN-8)
Compatible	Macintosh running System 6.0.7 or later
Model	M2001
Power	360 W maximum

The Apple Personal LaserWriter 300 is a compact monochrome laser printer introduced on 1 June 1993. It has no PostScript interpreter and no processor: the Macintosh renders each page with QuickDraw and sends it over a serial link. Apple's specification table lists the processor and the ROM as "N/A".

It prints at 300 dpi and up to 4 pages per minute on a Canon engine, with a minimum life of 100,000 pages. It has no power switch: Apple's note is that "once you plug in the printer, it is on and ready to print". With the I/O board removed, the engine can print a service test page on its own (see Service test page).

Specifications

Apple's figures from the Apple Service Guide for LaserWriter Printers, Volume 2:

Printer specifications

Item	Value
Engine	Canon engine
Print resolution	300 dots per inch
Speed	4 pages per minute maximum; actual performance depends on the application
Paper feed	In: automatic with universal paper cassette; manual feed for special materials. Out: face-down or face-up
Print materials	Cassette feed: 17-20 lb single-sheet photocopy bond. Manual feed: 17-28 lb, letterhead and coloured stock, standard-weight transparency material, envelopes and labels
Paper capacities	In: cassette 100 sheets; manual single sheets. Out: 25 plain sheets face-down. Transparencies, labels and postcard stock are delivered face-up only and must be removed by hand
Imaging language	QuickDraw
Macintosh requirements	Macintosh computer with System 6.0.7 or later
Imageable area	Maximum printable width 8 in. (203 mm); minimum margins 0.25 in. (6.35 mm)
Dimensions	Height 6.3 in. (16.1 cm); width 15.2 in. (38.5 cm); depth 14.9 in. (37.9 cm)
Weight	15.4 lb (7 kg) without cartridge
Operating requirements	50-90.5 °F (10-32.5 °C), 20-80% relative humidity
Power	U.S./Japan 100-120 VAC, 50-60 Hz; Europe/Australia 220-240 VAC, 50 Hz

Apple's separate technical specification sheet gives the electrical load as 360 W maximum, 3 A, 1231.2 BTU/hour, at 100-115 V, 50-60 Hz.

I/O board specifications

Item	Value
Processor	N/A
RAM	4 MB
DRAM	512K, expandable to 1.5 MB or 4.5 MB
ROM	N/A
Interfaces	RS-422
Printing protocols	QuickDraw
Built-in fonts	Avant Garde, Bookman, Chicago, Courier, Geneva, Helvetica, Helvetica Narrow, Monaco, New Century Schoolbook, New York, Palatino, Symbol, Times, Zapf Chancery, Zapf Dingbats

Apple's service guide prints both a "RAM: 4 MB" row and a "DRAM: 512K, expandable to 1.5 MB or 4.5 MB" row. The DRAM figures match the upgrade Apple documents for the LaserWriter Select 300, where 512K of soldered DRAM goes to 1.5 MB with a 1 MB 70 ns SIMM or to 4.5 MB with a 4 MB SIMM. Apple's technical specification sheet gives one RAM slot with minimum and maximum RAM of 0.5 MB. For the LaserWriter Select 300, the same guide lists the same fifteen font families as "39 fonts from the following font families".

Safety

The printer has an invisible laser, a hot fuser and a high-voltage supply. Apple's warnings for the LaserWriter family:

• The laser is Class 3B, 780 nm, 5 mW maximum, and its beam is invisible. Never disconnect the beam-detect cabling or the laser shutter with the printer on; the reflected beam can permanently damage your eyes. Never remove the cover of a laser/scanner assembly, powered or not. Keep screwdrivers and other shiny objects out of the beam path.
• The fuser becomes very hot. Switch the printer off for at least five minutes before servicing it.
• Switch off and unplug before servicing. With the covers off and the printer powered, do not touch the high-voltage power supply, the DC power supply, the power supply block, the high-voltage contact assembly or the power supply unit.
• Do not be grounded when working on plugged-in equipment or making live adjustments. Remove rings, watches and other jewellery.
• Toner is non-toxic. Remove it from skin and clothing with a dry tissue, then cold water; hot water sets it into fabric. Toner attacks vinyl.
• LaserWriter I/O boards use CMOS parts; handle them by the edges.

This printer has no power switch, so unplugging it is the only way to turn it off. Apple's troubleshooting step for a dead fan says to unplug it and, "due to the possibility of a capacitor error, wait 4 minutes" before plugging it back in.

Status LEDs

There are three LEDs on the top of the printer:

Status LEDs

LED	Colour	Behaviour
Ready	Green	Flashes during warm-up and while the printer is operating. Steady when warmed up and ready to print. Off when the printer is not ready, an error condition exists, or the top cover is open
Paper-Out	Red	On and steady when the printer is out of paper, or the paper tray is missing and the printer is set for cassette feed
Paper-Jam	Red	Comes on when paper jams inside the printer, and stays on until the jam is cleared

The Ready LED going off is the general error indication; Apple documents no blink codes.

Paper path and sensors

Paper enters from the cassette or the manual-feed slot and leaves through the face-down tray on top or the face-up slot at the back. The paper delivery selector chooses which: down for face-up delivery, up for face-down. The default is face-down.

There are four paper sensors. Each is an actuator and a U-shaped photo-interrupter soldered to the controller assembly, tripped by an arm or lever as paper passes:

Paper sensors

Sensor	Name	What it detects
PS301	Paper delivery sensor	Paper passing through the fuser assembly
PS302	Registration paper sensor	Paper in the manual-feed slot, and misfeeds of cassette-fed and manual-fed paper
PS303	Winding paper sensor	Paper passing from the photosensitive drum to the fuser
PS304	Cassette empty sensor	Whether the cassette contains paper

Service test page

The service test page exercises the print engine alone. Several of Apple's troubleshooting tables turn on whether a fault appears on the service test page (the engine) or only when printing from the Macintosh (the I/O board, cable or host).

Apple's procedure:

1. Remove the printer cover.
2. Install a toner cartridge and fill the paper cassette. Install the cartridge before plugging the printer in, or you may get a paper jam.
3. Plug in the printer.
4. Defeat the paper delivery sensor, PS301, with a piece of folded paper. Insert it only until it touches the metal shaft of the fuser; pushed too far, it leaves the sensor open and the printer reports a jam.
5. Cover the toner cartridge with a piece of paper to keep light off the drum.
6. Press down on the toner cartridge and on the cover interlock actuator while pressing the service test page button with a screwdriver.

When the cover interlock actuator is pressed down, the fan should come on and the paper delivery rollers should turn. If the fan does not run, the delivery sensor is not properly defeated, the interlock is not fully down, or the cassette is not installed. If the toner cartridge is not pressed down firmly during printing, the page may come out blank because the cartridge is not touching the HVT connector. The test page is a series of vertical lines.

Adjustments

Mirror adjustment

The reflecting mirror is set at the factory. After replacing the mirror or the laser/scanner assembly, readjust it:

1. Align the adjustment scale on the mirror assembly with the mark on the printer chassis.
2. Load letter paper and print a service test page.
3. Draw a line across the top of each vertical line on the page, and trace the top edge of a triangle set against the first vertical line.
4. Measure the error between the two lines.
5. If the error is more than 1.5 mm, shift the scale in 1 mm steps. Shifting the mirror towards the laser/scanner moves the left side of the image up; shifting it away moves the right side up.
6. Reprint and repeat until the error is under 1.5 mm.

Registration adjustment

Required whenever the controller assembly is replaced. Optimum leading-edge registration is 2 mm.

1. Set VR301 on the controller assembly to "0" with a jeweller's screwdriver.
2. Switch on and let the printer warm up.
3. Print three service test pages.
4. Measure the distance from the top of each page to the edge of the printed pattern, and average the three.
5. Adjust VR301 so the average becomes 2.0 mm, using Apple's conversion table (Figure 16): clockwise settings when the average is under 2.0 mm, counter-clockwise when it is over.
6. Print three more and repeat if necessary.

Apple's worked example in the text (an average of 2.6 mm, a difference of 0.6 mm, "set VR301 to a setting of -2") does not agree with its own table, which gives +2 for a difference of -0.61 mm when the average is over 2.0 mm. Check the result with a second set of test pages.

Troubleshooting

Pre-power-on checklist

Apple's list of things to confirm before chasing a fault:

• Line voltage is 115 VAC ±10%
• The printer is on a solid, level surface
• Room temperature is 50-90 °F (10-32.5 °C) and humidity 20-80%
• The printer is not in a hot, humid or dusty place, near open flames, or in direct sunlight
• The printer is not exposed to ammonia gas
• The printer is in a well-ventilated area
• Cables and connectors are OK
• The toner cartridge is installed and has toner
• The paper cassette is properly loaded, and the paper is within specification
• The top access door and rear door assembly are closed

Things that are not faults

• No power switch: plugged in means on.
• A uniformly light page. Apple's remedy starts with rocking the cartridge to redistribute toner and adjusting print density in the Print dialog's Options.
• A blank service test page with the cover off: the cartridge is not pressed down onto the HVT connector.
• A cartridge fogged by room light may recover if left somewhere dark, such as a drawer, for several hours. Keep it out of sunlight.

Self-inflicted faults

• Plugging the printer in without the toner cartridge fitted. Apple lists this as a cause of no paper pickup and of jams in the pickup/transfer area; install the cartridge, then unplug and plug back in.
• Leaving the rear access door open with a cartridge installed, or leaving the cover off. More than five minutes of room light can damage a cartridge and produce blank patches or black stripes.
• Loading already-printed pages into the cassette. Use manual feed for second sides.
• Inserting the folded paper too far when defeating PS301, which leaves the sensor open and makes the printer report a jam.

Engine checks with a meter

From Apple's troubleshooting tables:

• Fan does not run: the voltage between J804-3 (FANON) and J804-1 (+12VGND) on the laser/scanner assembly should change from 0 V to about 12 V DC when the printer is plugged in. If it does, replace the fan. If it does not, check fuse FU101 on the controller assembly; if FU101 is intact, replace the controller assembly.
• No pickup from the cassette: with the fuser assembly removed, the resistance between J204-1 and J204-2 should be about 440 kΩ. If it is not, replace the fuser assembly. Then check continuity between J103-1 and J103-2, and replace the fuser assembly if it is open.

Symptom tables

Apple's flowchart splits the machine at the service test page, then hands off to numbered tables. Summarised:

Symptom	Apple's table	First things to check
No power to fan	Table 1	Cartridge installed; cover and rear door seated (or interlock depressed and PS301 defeated); outlet voltage; power cord; fan cable seated and not pinched under the securing tab; J804 voltage; fuse FU101
Main motor failure	Table 2	Motor seated against the controller assembly; then motor, then controller assembly
No pickup from cassette	Table 3	Cassette selected in the Print dialog; cartridge installed before plugging in; known-good paper; not overfilled; pickup roller worn or deformed; pickup solenoid; fuser seating; J204 resistance; J103 continuity
No pickup from manual feed	Table 4	Manual feed selected; known-good paper; not overfilled; arm registration assembly broken
Jams in pickup/transfer area	Table 5	Known-good paper; cartridge installed before plugging in; physical obstructions; arm registration assembly; winding paper sensor on the feeder guide assembly; does it jam on a service test page
Jams in fuser/delivery area	Table 6	Known-good paper; obstructions; winding paper sensor; delivery roller assembly and passive delivery rollers; paper delivery selector movement; paper delivery sensor in the fuser
All-blank page	Table 7	Sealing tape still on the cartridge; pressure on the cartridge when printing with the cover off; dirty contacts on the cartridge or HVT connector assembly
All-black page	Table 8	Swap the controller assembly; if unchanged, the laser/scanner assembly
Uniformly light or faded	Table 9	Rock the cartridge; adjust print density in Print, Options and run a dozen pages; known-good cartridge; dirty HVT contacts; then transfer roller, HVT connector, controller, laser/scanner
Uniformly dark	Table 10	Print density; dirty HVT contacts; then controller, then laser/scanner
Black vertical lines	Table 11	Known-good cartridge; does it happen only when printing from the Macintosh? If so, the I/O board. If not, fuser then laser/scanner
White vertical lines	Table 12	Obstruction near the laser opening casting a shadow on the drum; Macintosh-only? I/O board; otherwise pickup motor, laser/scanner, mirror
Irregular smudged vertical banding	Table 13	Replace the toner cartridge
Stairstepping, jagged vertical lines	Table 14	Laser/scanner seated against the scanner interconnect assembly; interconnect seated against the controller; does it appear on a service test page? If not, I/O board
Horizontal banding	Table 15	Interrupt a print cycle and look at the drum. If the fault is on the drum, replace the cartridge; if not, replace the fuser
Bad registration	Table 17	See the registration adjustment above

The question that runs through these tables is whether the problem occurs only when printing from the Macintosh, and never on service test pages. If so, the print engine is working and the fault is in the I/O board or beyond it.

Serial connection

The printer connects to a Macintosh with a standard peripheral-8 cable to the mini-DIN-8 port on the back. If it is plugged into the Macintosh's printer port rather than the modem port, AppleTalk must be inactive in the Chooser.

Apple's RS-422 mini-DIN-8 pinout, from the general information section of the same guide:

Pin	Signal	Description
1	HSKo	Handshake out
2	HSKi	Handshake in
3	TxD−	Transmit data −
4	GND	Signal ground
5	RxD−	Receive data −
6	TxD+	Transmit data +
7	GPi	General-purpose input
8	RxD+	Receive data +

Parts

Selected entries from Apple's parts list for the M2001:

Part	Number
Controller assembly (120 V)	661-0029
Controller assembly (240 V)	661-0028
I/O board	661-0030
Laser/scanner assembly	661-0027
Fuser assembly (110 V)	661-0025
Fuser assembly (220 V)	661-0026
Fixing film assembly (110 V)	922-0450
Fixing film assembly (220 V)	922-0451
Paper pickup roller	922-0474
Pickup motor (pickup assembly)	922-0452
Pickup solenoid	922-0458
Arm registration assembly	922-0470
Feeder guide assembly	922-0469
Delivery roller assembly	922-0466
Passive delivery rollers	922-0467
Transfer roller assembly	922-0476
Mirror assembly	922-0468
Scanner interconnect assembly	922-0457
HVT connector assembly	922-0453
Motor assembly	922-0455
Fan	922-0456
Universal cassette	922-0459
Rear door assembly	922-0464
Cover interlock actuator	922-0475
Fuse, 125 V 10 A (pack of 10)	922-0484
Fuse, 250 V 3.15 A (pack of 10)	922-0486

Apple's full list also covers the chassis, covers, screw and hardware kits and regional power cords.

Comparison with the LaserWriter Select 300

The same Apple service guide covers the LaserWriter Select 300:

	Personal LaserWriter 300	LaserWriter Select 300
Engine	Canon	Fuji Xerox
Speed	4 ppm	5 ppm
Resolution	300 dpi	300 dpi
Imaging language	QuickDraw	QuickDraw
Interface	RS-422	RS-422
Processor	N/A	N/A
DRAM	512K, expandable to 1.5 MB or 4.5 MB	512K soldered, expandable to 1.5 MB (1 MB 70 ns SIMM) or 4.5 MB (4 MB SIMM)
ROM	N/A	32K
Input capacity	100-sheet cassette	250-sheet universal cassette; legal and envelope cassettes optional
Output	25 sheets face-down; face-up slot	Face-down
Paper weight	17–20 lb cassette, 17–28 lb manual	20–28 lb bond
Dimensions	6.3 × 15.2 × 14.9 in.	8.0 × 15 × 18.3 in.
Weight	15.4 lb (7 kg)	26.4 lb (12 kg)
Service test page	Press the test button with PS301 defeated	Jumper P32-1 to P32-2 on the DC controller board

Neither model prints a start-up test page when switched on.

Documentation

• Apple Service Guide Laserwriter Printers Volume Ii Sept 1993: Tab 4, Personal LaserWriter 300 (exploded view, parts list, specifications, adjustments, troubleshooting tables).

See also

• Apple LaserWriter Printers Volume I
• Recommended Tools