Mine did the same thing about a week ago after owning the TV for 18months.
Looked around the net, and downloaded the Service Manual for the TV.
7 Blinks is The SC, SU or SD card.
After looking around the Net, noticed this is a very common problem. Phoned Panasonic Directly, and by asking for the Part # by its complete technical part # (For the SC board), they were willing to sell it to me for $108 usd dollars, (The SU & SD boards are about $123).
They gave me another # to phone to get an authorization #, who then told me that Panasonic was covering the 7 Blink problem under warrenty up to 2 years.
As I'm in Canada, I then phoned the # they gave me, who also told me it was covered untill they realized I was in Canada.
They then refered me to a Canadian #, who after "A discussion with her manager" has authorized to replace the board, but only if I pay either $200 to take the TV in to an authorized repair depot, or pay $300 to have a tech come out to site.
Does anybody out there have access to panasonics internal repair websites, who can tell me which part of the SC board normally blows?
I suspect that it is as simple as replacing a transistor and would be considerably cheaper than the other options, plus providing those who own tv's that are no longer under warrenty an option to repair them other than throwing them out. (AS the repairs are starting to cost as much as a new TV.)