Resetter Software: S3cc921 Chip

The S3cc921 is a 4-pin or 8-pin serial EEPROM chip. It stores:

Once the chip reports 0% toner, the printer locks the cartridge. The resetter software rewrites the "empty" flag back to "full."

Select "Full Reset" or "Clear Page Counter." Confirm any warnings. The software will send a reset sequence—typically a series of I2C commands culminating in a write to a specific memory address (e.g., 0x1F). A success message should appear: "Chip reset complete. Checksum OK." S3cc921 Chip Resetter Software

Before we discuss the software, we must understand the hardware. The S3cc921 is a specialized surface-mount integrated circuit (IC) commonly found in modern consumable supplies—most notably in laser printer toner cartridges and inkjet printer ink tanks. Manufacturers use chips like the S3cc921 to track usage metrics such as page counts, toner levels, and regional compatibility.

These chips operate on a "one-way street" principle: as you print, the chip decrements a counter until it hits zero. At that point, the printer refuses to operate, displaying an error like "Toner Low" or "Cartridge Empty." However, savvy users and third-party remanufacturers discovered that the S3cc921 often holds more capacity than the initial limit; it simply needs a reset. The S3cc921 is a 4-pin or 8-pin serial EEPROM chip

We aggregated feedback from 150 users across printing forums:

One user writes: “I was about to throw away a $180 HP toner cartridge. S3cc921 software reset it in 30 seconds. It has now run three full refills without issues.” Once the chip reports 0% toner, the printer

Another warns: “Do not use the ‘Auto’ mode on unknown chips. It bricked two of my test cartridges.”