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Are the cartridges you are trying, genuine Dell-made ink cartridges?
Are they the right type of Dell cartridges, for this printer model? (If you tell me the cartridge 'type number', then I can verify this point for you.)
If the above points are not indicators of anything wrong, then try turning Off, and unplugging, the printer (with no cartridge in the affected slot) for at least 2 hours.
And when you put the new cartridge in next time, do not wear either a sweater, nor anything woolen in the way of clothing. Such clothes accumulate static charge, then when a new cartridge is put into the printer, it can cause a static 'zap' to get into the cartridge recognition circuitry and cause failure to recognize new cartridges, etc.