An introduction to Canon Error Codes

Like other brands, Canon copiers and printers are equipped with a mechanism to check the condition of the machine. It runs a check as needed, and will indicate an error in the control panel upon detention.

If an error is detected, the machine may be reset by turning it off and then on; however, this does not apply to E000, E001, E002, E003, E004, E005, E013, E020 or E717, preventing the user from casually resetting the machine when the fault is serious e.g., melting of the thermistor; otherwise, the fixing heater would overheat or toner would flow out of the hopper. If fault is identified as E000 through E003, the power switch will automatically go off in some models in 30 seconds if it is turned on. In the case of E004, power switch will go off in about 3 seconds. An authorized technician should reset E000, E002, E003, E004, E005, E013, E020 or E717. The table that follow indicate the nature and timing of detection of each error.

E000 to E399               Codes relating to the copier
E400 to E499               Codes relating to the feeder
E500 to E514               Codes relating to the finisher
E530 to E595               Codes relating to the finisher
E5F0 to E5f9               Codes relating to the saddle stitcher
E601 to E830               Codes relating to the copier

fix for TN250 cartridge in an MFC 6800

Anybody have a fix for TN250 cartridge in an MFC 6800.
Same problems with low toner light. Also out of toner caused shutdown. Managed to get it going again by cycling power on and off.
My problems have got worse after using after-market toner cartridges at ~$8 each but I can live with them (save $32 ).
Summary of my problems are
1 Toner shading intermittent. Sometimes gets worse as more copies are done. Sometimes starts bad and improves.
2 There is toner in cart and I would like to get low toner light off.
3 Occasional out of toner shutdown.

I have looked at the TN250, both brother and after-market, and see no window to cover!
Thanks for listening