Epson 4900 printing red

I have had my 4900 for three years and it has been fine. The other day when I started to print with it I am getting a red overcast to any image I print. They print fine on my p600 using same pc and printing software but the 4900 gives a lot of red. Any ideas as to what is going on? This is an update from the first part of THIS post. I took a second look at my nozzle check and there is no discernible difference between the magenta and light magenta. I know I filled the cart with light magenta because I still have my bottle of magenta that I haven’t used yet

I believe you have settled pigment in your dampers and lines and if the ink is 3 yrs old (magenta) it is expired.

You need a new bottle of magenta. Refill the cart, agitate all carts, reprime them, run a power cleaning on the printer.

best,
Walker

I need more clarification please, the ink is less than i year old and it is light magenta if that matters. Also can i empty out the cart for a new bottle of light magenta as the cart is still 2/3 full?