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Imagewriter II condition varies with time in service

Imagewriter II's are good Mac printers, but over time they will wear out. The "wear" is generally not mechanical - although print heads sometimes fail - but some of the "chips" or transistors or drivers WILL fail over time.

The Imagewriter II printer produces a lot of internal heat. Components that control the current (power) to the print head and to the motors produce the most heat. Heat is the enemy of all semiconductors. Over time, excessive heat will cause these components to fail. For the most part, it is hard to estimate the time to failure, as it depends on how often the printer was used, how long it ran during the day, and how hot (or cool) the room was where the printer was used. We just don't have that information.

These printers support a "self-test" function that will print across the page, over and over again, without a computer. We test Imagewriter II printers for five minutes of this CONTINUOUS PRINTING operation, but we have found that printers will self-distruct if left to run in this mode for terrribly much longer. We then follow with five minutes of continuous carriage (head) movement, another self-test; and then we check the printer for noise from the power supply (a sign of possible problems) and print quality.

Although we make these efforts to eliminate printers that may have problems, we cannot guarantee or warrent the printers we sell for any extended period of time. Consequently, we have set the price of these printers with the expectation they will perform adequately under occasional use.

If you want a printer that will be more likely to operate in a business environment for regular use, powered up and printing for several hours a day, we can try to accomodate you by picking printers that were built more recently (i.e. have a higher serial number) and/or which appear to have seen less use. We may charge extra for this service. Ask for details.

Imagewriter II printing setup and tests

It is important to set the printer's "switch settings" correctly for proper operation of the printer. If you remove the top cover to expose the print head area and (with the power off) gently move the print head mechanism to the right (with the front of the printer closest to you), you will see on the left a set of DIP switches. One of those switches must be set to enable or disable the Appletalk feature. If you have set up your Macintosh to operate the printer WITHOUT appletalk, and Appletalk is enabled, or if your Mac expects Appletalk and the printer's Appletalk option is DISABLED, you will not get correct printing: the printer will print garbage and the head will move in large jumps, and so on.

Appendix C of the Imagewriter II manual describes these switch settings: only one switch is changed between Appletalk and non-Appletalk mode. Or, you can use Chooser in your System Folder to turn Appletalk on or off (provided there is no other Appletalk device on your serial port) to see if that makes a difference. The Appletalk option (or the 32K memory buffer option) is a small, long circuit board that is installed underneath the front cover of the printer, the cover that also contains the power and other buttons on the front right of the printer.

The switch settings should be as follows:

_____SW 1____________SW 2____
O O O O O C O O | C C O ? X X

Imagewriter II self tests

Irrespective of the settings of the switches, you can test the printer as follows. Install paper and the ribbon as normally, and plug the printer AC line into the wall socket. Turn the printer OFF with the power switch. PRESS AND HOLD the "form feed" button down, and then press down the POWER switch. THEN and only then release the form feed button, followed by releasing the POWER switch. This will put the printer into a "test print" mode where it will print the alphabet over and over again. IF you press and hold the "line feed" switch instead as described above, it will put the printer into a "test carriage" mode, and the print head will move back and forth across the paper without printing or advancing the paper.

PLEASE NOTE the print test for continuous printing is a VERY AGRESSIVE TEST and heats up all the components of the printer. These printers are now several or more years old and well past their design lifetime. The continuous printing test should not be run for more than a few minutes. Excessive or prolonged operation can and will lead to damage of components and the failure of the printer.

Copyright © 1998 Herb Johnson
Most recent revision May 24 1999