How does printer know when toner is low?

[Stumped2]

My Brother MFC-L2700DW All In One indicated low toner & stopped printing. I put in a new aftermarket LN660 toner cartridge just like I was using, but the printer still said low toner & would not print. I did a reset using the front panel buttons & this got it working.

I don't know if this is cartridge or printer problem. But how does the system know the toner is low? The printer does not use chipped cartridges & there are no electrical contacts on the cartridge. If it just counted the number of printed pages then the cartridge would always be replaced after the same number of pages but it does not. How does the system know the toner is low?

 

[thebestcpu]

Hi @Stumped2
I am no expert, yet they typically have a toner counter and a drum counter keeping track of when it gets low. There are situations where they don't work right and need resetting. The link to this article goes over these topics, though the steps might be a bit different for your particular Brother printer:
Brother Printer Troubleshooting
Hope that helps
John Wheeler

 

[Stumped2]

Hi @Stumped2
I am no expert, yet they typically have a toner counter and a drum counter keeping track of when it gets low. There are situations where they don't work right and need resetting. The link to this article goes over these topics, though the steps might be a bit different for your particular Brother printer:
Brother Printer Troubleshooting
Hope that helps
John Wheeler

Thanks for the reply & link.
The only explanation for the problem is what you mentioned, it's "a common problem with Brother printer". Everything else in the system is OK.

I found a service manual online & some of the error codes have these descriptions:
1) Estimated remaining toner amount based on the rotations of developer roller
2) Dot count or develop roller counter of the toner is reaching the upper limit.
3) Dot count or develop roller counter of the toner has reached the upper limit in the toner stop mode.

Again as you said, it just counts a roller rotation.

Thanks again.

 

[thebestcpu]

Thanks for the reply & link.
The only explanation for the problem is what you mentioned, it's "a common problem with Brother printer". Everything else in the system is OK.

I found a service manual online & some of the error codes have these descriptions:
1) Estimated remaining toner amount based on the rotations of developer roller
2) Dot count or develop roller counter of the toner is reaching the upper limit.
3) Dot count or develop roller counter of the toner has reached the upper limit in the toner stop mode.

Again as you said, it just counts a roller rotation.

Thanks again.

You're welcome @Stumped2
John Wheeler

 

[Epatcola]

But how does the system know the toner is low? The printer does not use chipped cartridges & there are no electrical contacts on the cartridge. If it just counted the number of printed pages then the cartridge would always be replaced after the same number of pages but it does not. How does the system know the toner is low?

The printer can estimate how much toner is used on each page the same as inkjets estimate how much ink is used from each cartridge.

Most (all?) Brother cartridges have a mechanical reset lever/wheel thing which tells the printer a brand new cartridge has been installed and so to reset toner usage counting. After a number of turns of the cartridge roller the reset lever thing trips. I think the number of turns needed indicates to the printer if it is a starter, normal, or high capacity cartridge installed.

I guess some (most?) 3rd party cartridges don't bother setting or maybe even having the reset lever so you have to manually reset the toner counting from the control panel.

If you search for Brother toner reset lever you will find some videos showing the mechanism.