We as well purchased the same HP Plasma Color TV and of course we heard the dreaded POP and the screen went black but still have the sound. Tried to contact HP but all they want is 629.00 in order to repair it. Seems the circuit board on the inside is faulty. It is an 89.00 part and HP is aware that all of us have had this issue but it is a major hassle trying to contact anyone who can help you and they do not offer any incentive to help replace the part.
I am so furious and for HP to be such a quality name in my opinion it is not.