Hi there and welcome Simon
E02805 means that the wrong ink tank was inserted. This can happen if using non-genuine inks or if the cartridge is expired. There will usually be a date on the package or the bottom of the cartridge to say whether or not it is expired. However it can also be caused by the mechanical sensor in the print head failing causing the print head to need to be replaced. Please follow these steps using both the new and the old cartridge to test it.Remove all the ink cartridges from the machineThen clean the contacts on the cartridges as well as inside the machine itselfDo this with a small amount of warm water on a cotton swab until no ink comes off on the swabIf any of the other cartridges are low, empty, leaking or bulging replace themThen turn off the machine and unplug it for 70 secondsPlug it back it and wait for the insert cartridges messageInsert the cartridges and check to see if the problem is still there
Let me know the results please.