Red streak getting wider on page

[Hanusborb]

Every page printed from my HP 2600 Laser printer has a red streak.
The streak is getting bigger. See attached picture.
The printer is telling me to replace the magenta cartridge bit it doesn't seem empty if it's streaking.

Should I replace the printer or the cartridges?

 

[Obtex]

Just replace the magenta toner. Theres some toner left, but the yield of the parts inside look used up