Install Black Cartridge HP P4015n error

[Machinercylr]

I have on the bench a n HP Laserjet P4015n that after paper,toner cartridge is installed and initializing instead after checking tonercartridge and it states "Genuine HP Toner Cart. installed instead of going to "Ready" it displays "Install Black Cartridge". I have tried another toner cartridge and still the same Error message. I have searched the web for Cold-Reset or Hard-Reset of this printer to see if by clearing memory of this it will come to "Ready", but nothing. Whas anyone delt with this? I don't think it is the chip reading sesor since it identified the Chip as a "Genuine"HP Product. The gate that is operated to open once cartridge is loaded in that is mounted above and is located to the right-side of the Laser unit,does this have a switch within this? Any help would be appreciated,Thanks in advance,Steve

[Big Al]

It might be that one of the contacts that mates with the toner cartridge is damaged. If you have a working 4015 pull the toner cartridge and look
closely at the contacts that energize and ground the cartridge. Then go look at the bad one and see if there are any differences.

Al

[cs_steve]

This error can also result from dirty contacts, I would wipe them down.