Hello, Sorry you're having problems. The set remaining with the Panasonic logo stuck on the screen is indicative of a hardware failure in the TV (the "Mainboard" more specifically), and in MOST cases requires replacement of that part.
However it's worth it to try a hard reset, as sometimes the processor in the TV can simply have locked up.
The first thing you would try, is disconnect the set from power, then press and hold the power button on the TV itself (not the remote), for 10 seconds and release. Then plug the set back in, and also check that the power cord is connected tight at the TV as well. Press power once, and see if the set powers up normally. Try this procedure up to 3 times, and please let me know what happens.
Are you still having the same problem? If so, how old is this TV please- is it just over or just under one year from the date of purchase?
I'm sorry to hear, and this is bad news. The TV's Mainboard has prematurely failed, and requires replacement. This part processes the external AV Inputs and when it fails- it leaves you stuck with the Panasonic welcome screen. Unfortunately there's no quick fixes, settings, adjustments, etc, that will fix this- as it is a hardware fault that's not uncommon with new flat screen sets these days.
I would strongly suggest contacting Panasonic about this and diligently complaining about the issue, as the TV needs an expensive repair (about 1/2 the cost of the TV to replace the mainboard) and in many cases I've seen manufacturers step up to the plate and fix this issue- even out of warranty.
You're welcome and best of luck with the set. The only other possible thing you can try on a user level for this, is to unplug the TV and all other peripherals form the set and leave it unplugged for several hours in the hopes that the processor resets- but offhand I do not have high hopes for this.
If you need further assistance let me know. Please do not forget to click at least a 3 STAR RATING, at the top of the page for my efforts. That is how the site credits me for my work.
You're welcome. Please do not forget to click at least a 3 STAR RATING, at the top of the page for my efforts. That is how the site credits me for my work.