Once upon a time, a laser printer had no way of communicating that a cartridge was nearly out of toner until it simply began spitting out blank pages. Today, most laser printers monitor toner levels through different means and give low-toner warnings before running out completely. Following are three varying methods utilized for detecting low toner:
1.) PAGE COUNTERS – Some printers have driver software that estimate toner level through page count. A new cartridge is expected to average a predetermined number of printed pages, so the printer ‘counts’ each page that runs through the machine until reaching that magic standardized number. Then it generates a low-toner warning. If your toner usage per page is low, there can be quite a bit of toner remaining beyond the triggered warning.
2.) TONER SENSORS – Some cartridges are equipped with sensors that start out covered in toner when the cartridge is full. The toner level decreases with each print job until it reaches a low level that triggers the sensor to communicate low-toner with an indicator light. By removing and shaking the cartridge, you can often print a fair amount of additional pages before needing to replace the cartridge.
3.) SMART CHIPS – More and more printers read toner cartridges using smart chip technology to monitor toner levels and communicate a low-toner warning. The upside is a more accurate measurement. The downside is that when the smart chip determines the toner has reached an end, the chip prevents any further print jobs until the cartridge has been replaced. Often, when a new cartridge is installed and there is a memory error or the printer will not print, the culprit is a defective smart chip.