Apple ImageWriter LQ Troubleshooting Guide

ImageWriter LQ (photo: All About Apple museum, CC BY-SA 3.0)

Fault finding for the Apple ImageWriter LQ, from the symptom charts in Apple's ImageWriter LQ Service Source and the troubleshooting chapter of the owner's guide. The adjustments the charts refer to (home position switch, card guide, print head gap, platen gap and parallelism, colour ribbon home position and parallelism) were in Apple's separate Paperless Printer file, which is not hosted here.

Before you start

• Run the self-test before suspecting the printer: with paper loaded and the Select light off, switch off, hold Form Feed while switching on and release it when the head moves. The test checks only the printer, not the cable, the connectors or the computer.
• In the symptom charts the cures are in order of likelihood. Try the first, check whether the symptom remains, then try the next; if you replaced a module, put the original back before moving on.
• Apple warns owners never to change a cable, an interface card or a DIP switch with the computer switched on.

Lights

Error light (Owner's Guide, Chapter 8; Service Source, Miscellaneous)

Indication	Meaning	Action
Error light on steadily (Select light off)	Out of paper, or paper not yet fed under the platen	Load paper and press Select
Error light blinking	Front cover open or loose, or something jammed in the print mechanism	Seat the front cover and press Select; clear any jam
Error light blinking irregularly	DIP switch 2-4 does not match the option card	2-4 open without an AppleTalk card, closed with one

Symptom charts

ImageWriter LQ symptom charts (Service Source)

Area	Symptom	Cures, in Apple's order
Power	Power light off, no carrier movement	External power and connection; voltage selector switch (international units); test the primary fuse; test the three secondary fuses; test the power switch; main board; transformer; noise filter board
Communication	No printing or garbled printing	Printer selected in the Chooser; DIP switches; interface cable tight; self-test (if it passes, run diagnostics on the main board; if it fails, replace the main board)
Communication	No communication with an option card fitted	DIP switch 2-4 on
Paper feed	No paper feed	Paper feed gear train clear; test the paper-handling change switch; test the paper feed motor; main board
Paper feed	Binding, tearing	Paper thickness lever; paper path clear; paper loaded correctly, with tractor holes on the sprockets
Paper feed	Paper bail does not open and close by itself	Test the auto-load solenoid; main board
Carrier	Carrier moves at power-on but does not return home	Test the home position switch; home position switch adjustment; main board
Carrier	Power light on, no carrier movement	Carrier area clear; test the carrier motor; main board
Carrier	Carrier hits the right-hand frame on four-part carbonless forms or the perforated edge of tractor paper	Forms no thicker than 0.55 mm; paper aligned; paper thickness lever; card guide adjustment
Carrier	Carrier hits the left-hand frame during the power-up home seek	Test the home position switch; adjust it; deflector pan seated against the platen bar; main board
Printing	Dots missing	Print head; main board; print head to relay PCB cables; relay PCB to main board logic cables
Printing	Printing continues when out of paper	Test the paper-out sensor; main board; paper detect sensor
Printing	Carrier moves, nothing prints	Main board; print head
Printing	Nothing printed, carrier still, power light on	Self-test: if it passes, see Communication; if it fails, main board
Printing	Printing garbage	Main board
Printing	Too light	Paper thickness lever; ribbon; print head gap adjustment; platen gap and parallelism adjustment
Printing	Too dark	Paper thickness lever; print head gap adjustment; platen gap and parallelism adjustment
Printing	Less than best quality from a Macintosh	The System file needs each font at the output size and at three times that size (non-TrueType fonts)
Printing	Prints with the front cover open	Test the cover-open sensor; main board
Printing	Uneven self-test, four lines light and three dark	The printer is sensing the colour ribbon carriage: press the black ribbon cassette fully down on the left so it operates the ribbon microswitch
Printing	Squashed lines or misregistration on pin-feed paper	Use the pull tractor and bottom feed slot with the paper stacked at least 12 in below the printer; keep cords out of the paper path; avoid printing in the top and bottom inch
Printing	Problems with labels or multipart forms	Pull tractor and bottom feed slot; do not back the paper out (especially labels); cut at a perforation and feed forward to remove
Printing	Printing on the platen or over the perforation with the push tractor	DIP switch 2-8 on, to load paper beneath the bail, about 1 in beyond the print line
Printing	Words touching or slightly overlapping	LQ driver 2.0 or later
Printing	Page setup differs between printers	Use Page Setup each time a different printer is chosen
Cut sheet feeding	No access to the second or third bin	DIP switches 2-5 and 2-6 set for the number of bins
Cut sheet feeding	Printer does not recognise bin 3	With the gear configuration pin in, bin 2 becomes the expansion bin; with it removed, the expansion bin becomes bin 3
Cut sheet feeding	Paper from expansion bin 3 skewed	Add 3.1 mm rubber bumpers to the bottoms of expansion bins 2 and 3
Cut sheet feeding	Documents go into the wrong bins	The application may not support multiple-bin feeding; every page then comes from the bin chosen under "First Sheet From"
Cut sheet feeding	Envelope feeding problems	Adjust the paper thickness lever for envelopes and reset it afterwards; do not mix cut sheets and envelopes in one job
Colour	Colour bleeding	Constant across the page: colour ribbon home position adjustment; increasing or decreasing across the page: colour ribbon parallelism adjustment
Colour	Wrong colour printed	Test the colour ribbon detect switch; test the colour ribbon home position switch (if faulty, replace the colour ribbon motor assembly); test the colour ribbon motor; main board
Colour	Only one colour printed	Test the colour ribbon motor; main board
Miscellaneous	Control panel switches do not work	Test the switches (replace the control panel board if faulty); main board
Miscellaneous	Intermittent network problems: head resets when idle or printing stops	Replace ROM 02 on the logic board with ROM 03

In the Cut Sheet Feeder chart Apple names switches 2-5 and 2-6; the Peripheral Interface Guide's table for the number of bins uses switches 2-5 to 2-7.

Owner's checks

• No power: the fuse is internal and Apple says only a dealer should replace it. Never fit a wire or a higher-rated fuse, and find the cause of a blown fuse before using the printer again.
• Garbled output or a one-line printout: usually a baud-rate mismatch. The LQ leaves the factory at 19,200 baud (switches 2-1 and 2-2 open); an Apple IIe serial card needs 9600 with both switches closed. Data format is fixed at 8 data bits, 1 start bit, 1 stop bit and no parity.
• Intermittently dropped or random characters: the factory handshake is DTR (switch 2-3 open); closed selects XON/XOFF. Match the software and interface card.
• Everything on one line, or unwanted double or triple spacing: only one of the printer, the software, the serial port or the interface card should add a line feed after a carriage return. The printer adds none at the factory setting (switch 1-8 open).
• Losing top or bottom margins over several pages: the printer is set so that the most it loses over time is two lines. Check how the paper is loaded (a form feed should bring the top of the paper to the top-of-form line on the paper guide), switch 1-4 for 11 or 12 in pages, and the software margins.
• Light or fading print: ribbon cartridge seated and threaded, paper thickness lever set. A single squashed line in a consistent place, or very fuzzy printing, means the ribbon tolerance needs setting by a dealer.

Related pages

• Apple ImageWriter LQ
• Apple ImageWriter LQ General Maintenance
• Apple ImageWriter II Troubleshooting Guide