Faced with a printer that would stop printing for no apparent reason, Finnish pirate and hacker [Janne] decided he had had enough. After doing a bit of research, he disassembled the drum assembly and replaced some components. The end result? Supposedly ‘broken’ printers started working again.
Apparently, Xerox uses a fairly basic scheme to determine when it’s time to replace your printer drum: An I2C eeprom keeps a count of the number of pages printed. After a certain number, the printer decides that it’s broken and won’t print any more. To fix this, a suitable replacement memory chip needed to be sourced. The original chip was a ST22C02WP. However, this was difficult to find, so the replacement part was selected to be a*CSI 24C01WI. Amusingly enough, the replacement part has only half the space of the original chip, but this doesn’t appear to have caused a problem. The chips were swapped, and after some precision soldering the printer was completely repaired. The blank replacement chip functioned… due to the fact that there is no security or encryption involved between the printer and the drum (Score!)
Have you ever had to get intimate with a soldering iron just to get your printer to do its job? Let us know in the comments.
Filed under: hardware
