Leo Mauler In response, I got sick of buying a printer cartridge every 6 months to a year because HP built in a circuit to EXPIRE the ink. Will cheep and free are my modes of operandi, spending 120$ a year for printer cartridges just so I can have the luxury of printing is stupid. If the wife hasn't thrown them out , I will give you two cartridges from the old HP and allow you to dissect them.
research can be found
http://www.theinquirer.net/en/inquirer/news/2003/04/29/hp-inkjet-cartridges-...
http://land.netonecom.net/tlp/ref/letters/hpPrinters.php
http://news.bbc.co.uk/1/hi/technology/4293427.stm
http://constitutionalcode.blogspot.com/2005/02/cartridge-expiration-date-wor...
http://www.mrtweak.com/laptop-and-desktop-hardware/stop-expiration-of-hp-ink...
http://www.engadget.com/2005/02/23/hp-hit-with-lawsuit-for-dead-ink-cartridg...
http://www.techdirt.com/articles/20050222/1220232.shtml
http://larko.wordpress.com/2008/01/13/your-printer-is-expired/
http://www.technewsworld.com/story/40826.html?welcome=1203205169
http://www.lawyersandsettlements.com/articles/00395/ink-jet-printers.html