Only black and blue will print on test page; yellow and magenta does not. Ink was just replaced.

Did yellow and magenta print OK before the previous cartridges ran out? If so, it looks like your new cartridges are not working properly. Try another yellow and magenta cartridge - you can re-use the previous cartridges if they turn out not to be faulty. If new cartridges don't solve the problem, you can try soaking the print head, in case you have nozzles blocked with dried ink for some reason.

Turn the printer on, and as soon as the print head moves out of its parking position, pull the power cord out of the back, or turn the printer off at the mains. You may now carefully move the print head by hand over to the left hand side out of the way. Look inside the print head parking area on the right and you will see a small rubber cup that comes up to cover the print nozzles when the head is parked (to stop it drying out). Use a syringe or dropper to fill this cup with head cleaning fluid or distilled water. DO NOT USE TAP WATER. Carefully push the print head by hand fully into its parking position so that the cup full of fluid comes up over the print head. Do not turn the printer on at any stage in this process. Leave this for at least 24 hours, then turn the printer on and try a head clean/nozzle check again. If you get any magenta/yellow ink on the nozzle check, then there is hope! Repeat the head clean/nozzle check process 2 or 3 times, but not more. Leave for 24 hours for any air bubbles to disperse. If nothing, repeat the soak process once more. If still nothing, post a new comment detailing what you have done and the results.