Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble. We’ll get started chatting here. I am also sending you an offer so you can reach me directly me by phone if preferred. Feel free to ignore it for now, it will be available to you at any time if you need to get more help after our chat.
Do you have any signs of life at all from the tv?
Is the power/status light lit up either solid or flashing?
If not, then the internal power supply board is defective. If yes, then the power board could still be the problem, as could the main board or several other components.
This is something that would require repairs to correct, which is much more involved than changing a fuse.
This issue could be a manufacturing defect, but is also often caused by a power event (shock/surge, prolonged over/under voltage condition, etc).
If you're thinking about a do it yourself repair, you'll need to be comfortable and skilled with electronics repairs, which would require dismantling the set (removing the back panel of the tv), diagnostics with a digital multimeter to test voltages inside, changing out boards as needed, and possibly desoldering/removing and soldering/replacing capacitors (a common failure point).
If you’re considering repair at a local shop, you’ll find a typical repair to be around $300 for diagnostics, parts, and labor.
For a 3 year old tv it is probably worth a moderate investment, as Panasonic plasmas tend to be quite reliable. You'll likely end up right on the border though where repair costs will not be a whole lot less than an entirely new tv, as costs have come down so much lately.
Depending how you'd like to proceed, I can give you some basic guidance and help finding parts, help finding a local repair shop, or recommending some replacement models.