printer problems

wonder if any members have had this issue before....i recently bought an unopened replacement tricolour cartridge for my hp printer....it will not print yellow, but comes out as green...now ive read that its a temporary printhead problem and one or two pages printed totally yellow should cure it, but this hasnt worked,,,before a buy another cartridge, or even worse, a new printer, does anyone else have any suggestions as to potential cause of this? the printer has never gave me any probs up to now....its only an inkjet but has been grand...
cheers

Ive had some poor quality colours before when buying unofficial inks for my epson but never that bad an issue

Only suggestion is - is it a genuine HP cartridge?

Not had any issues with my HP printer using genuine HP cartridges

Chris

thanks guys for replying, yeah chris its a genuine hp tricolour cartridge, unopened and in date, i'll try another one i guess.....