This type of drum and powder printer has an initial print volume set at the factory. (With the factory comes with the toner cartridge, the printing volume is relatively small)
When this printing amount is exhausted, it indicates that the toner is insufficient, whether there is powder or not.
Replacing the chip on the cartridge can actually be seen as a one-time reset \"print volume\" device.
(Although there are methods and interfaces that can directly modify the printing amount, but different models of the interface is different, modify the printing amount and need to dismantle the machine, it is not as convenient as directly changing the chip, so there is no direct sale of this interface equipment on the market)
And this counter also has a set upper limit (generally around 1200-1500), for example, you can not set this counter to 99999 or something like that.
When the counter counts to 0, it prompts you to change the toner cartridge, and at this time, fill a powder and change the chip to be used again.
Color spray is the same principle. But at present, some ink cartridges are changed to provide color spray, there is a small button next to the chip, you can reset the counter at the same time randomly assigned a serial number, sometimes the serial number is not right, the original good cartridge is not normal, you have to continue to press several times, until the several cartridges are identified correctly to use...