The flashing light 7 times suggests a main board failure, you will likely see this fault develop and get worse.
Since this is a hardware fault, your not going to be able to reapir this with a software upgrade or a setting change in the menu.
I suggest you take the unit into a service centre for repair, if you provide your postcode I can recommend a suitable firm to repair the TV.
Sorry for the delay, I wanted to speak with the service centre to give you a ball park cost.
I would suggest you use the approved Panasonic repair centres for this type of repair so the work is covered by the Panasonic warranty, your nearest centre is DBS who are about 30 miles from you.
They charge £40 inspection fee, if you then chose to have it repaired they charge a further £40 for labour costs, so your looking at £80 + parts to have it repaired.
DBS can be contacted on 01904 692266 or via their website :www.dbsservicecentre.co.uk
I just wanted to follow up to find out how you got on with your TV repair, and find out if I can be of any further assistance?