HP Vivera Print heads

Bonjour all… have been given a HP Officejet Pro K550 for the home office. Don't think it has been used for a while and after installation on the mac, I have found out that the it only prints using cyan and magenta!!:icon_mad:

Looking at the on-board utilities widget thingie-ma-bob it is saying that the cartridges are all 3/4ers full (one for each process colour) and that both print heads are in good working order.

It seems to me that the c/m print head is fine as is. but the y/k print head is (i'm guessing) dried up and blocked.

Have run a few of the self-clean programmes but no joy!

So, anyone out there know a way of cleaning / unblocking a dried up print head?
i'm guessing (again) that it needs to sit in a bath of alcohol for a hour or two (wish i could do the same!!!) to de-clog the dried up ink. Anyone else know what will work?

If i need to spend the £50 odd to get a new one i will, but would like to see if i can get a 'claimed ok' piece working first.

Thanx a million.

Ok have found out the answer for myself. It is the alcohol bath thats needed. So next question for you all (or myself in a couple of weeks!) Where can i get pure alcohol from????

Have tried various places (boots/asda pharmacy et al.) but the best they can do is surgical spirit. Am going to give this a go me thinks, or am i better off using vodka??