c451 saying magenta toner is low

[TugmysterUK]

I have a c451 machine that says magenta toner is low and then finally says replace but when u remove the cartridge it has still got about half still in it ( rought Guess ) but it is no way empty.when u put new one in it says toner low.
I have put the latest firmware on, ive done a data clear, ive swapped over the cluches that drive the toner cart, swapped sensors and cleaned out toner hoppers but its still playing up. Ive checked over the contacts were the toners meet and tryed loads of different toners.
IU unit has not reached life but is now getting near when problem fisrt appeared it was 3/4 gone.
Any help would be appreciated, thanks in advance.

Steve

[konikilla]

Hi Steve,

The toner in the machine will be measured from a sensor inside the Imaging Unit. The toner unit senors only really detect that a toner unit is installed not how much is in it. The senor inside the imaging unit will detect how much toner is mixed with the developer contained within the IU and this is what it is detecting is low and showing up your toner low message. If you change the IU it should sort out your problem.

Al.

[pepper38_cnd]

The toner low message can be generated by the counter on the toner cartridge chip ( Change toner soon on some machines ) or when the toner density level in the IU takes too long to increase when calling for toner, after calling for toner for a specified period and not seeing the level increase the replace toner cartridge message is displayed. If you are getting the same symptoms with a new toner cartridge either the add toner motor is not working, the toner system is clogged, or the IU is defective. I'm asuming the IU is not rechipped and the toner is OEM.

[TugmysterUK]

all sorted thanks 4 all ya help it was the toner hopper assy replaced today works fine.