Methods to determine whether the toner cartridge needs to be replaced are:

①Check the print quality. If the printed text is unclear, has missing prints, ghosting, blurring or uneven colors, this is usually a sign that the toner cartridge needs to be replaced.

②Observe the surface condition of the toner cartridge. If the surface of the toner cartridge has obvious wear, scratches, cracks, or discoloration, these are signs that the toner cartridge is worn and may need to be replaced.

③Check the toner cartridge life and the number of pages printed. Many modern printers have a recording function for toner cartridge life, which can be viewed in the printer's settings. When the life of the toner cartridge reaches or exceeds the expected number of printed pages, replacement should be considered.

④Pay attention to the printer notification light. If the printer's light changes color or gives other indications, this is usually a signal to replace the toner cartridge.

⑤Observe the printed paper. If your printed paper shows patches, dark spots, or uneven colors, this may be a sign that the toner cartridge has run out of powder.

⑥Consider the number of times the toner cartridge can be reused. If the toner cartridge supports refilling or recycling, but has been refilled many times, you may encounter problems such as color fading, black spots, or black and white bars, which indicates that the toner cartridge is about to be exhausted and needs to be replaced.

In short, you should consider replacing the toner cartridge when the print quality deteriorates, the toner cartridge surface is damaged, the life expectancy is reached, or the printer prompts for replacement.