Samsung ML-2851ND/SEE Service Manual page 107

4.2.5.4 Error related in a toner sensor
It explains a message related in toner sensor in a LED.
4.2.5.4(a) Invalid Toner
- Contents: The red LED turns on when a supplier is different between a toner cartridge and a set.
- Solution: Attach a suitable toner cartridge (the same supplier's) to a set. (A unique key has been applied.)
4.2.5.4(b) Low Toner
- Contents: When a toner in the toner cartridge almost ended, the red LED is blinking.
- Solution: It means that a toner in the toner cartridge has been almost ended. Repare the new toner cartridge.
4.2.5.4(c) Replace Cartridge
- Contents: Turning the red LED on means the life span of a toner cartridge (except a toner part) has been ended.
- Solution: If an Toner Cartridge Life cycle Probreum, in a worst case, a toner overflows and it may cause a system fail.
Therefore, recommend a user to replace a toner cartridge.
Service Manual
Alignment & Troubleshooting
4-57
Samsung Electronics