Can't print on HP Deskjet 820 Cxi

[anxo dulcinea uc3m es (Angel `Anxo' Sanchez)]

I have just installed Red Hat 4.2 on my PC and apparently 
everything went smoothly. However, my HP Deskjet 820 Cxi 
printer won't print no matter what I do. It does not even 
react when trying the test "print ASCII directly to port". 
I've tried using the different filters provided, although
the one that looks closer is the one for HP Deskjet 500 
series. Is it a filter problem, or is there something else
I need to do for this printer? 

Help will be greatly appreciated. 

Angel