Hello, Sorry you're having problems. What it means is that the Plasma display processing in the set has a failure in one of the components (this is made up of the Sustain boards, Driver boards and the Plasma display panel itself). While Panasonic sets are designed with error codes (1-13 blink patterns) these codes simply point to a STARTING point for a Tech to begin troubleshooting, which requires removing plugs, checking for a change in blink codes, and also measuring live voltages using a Multi-meter.
In most cases on a 50" Panasonic Plasma, you are looking at either failed Sustain boards (between $300-$450 parts and labor), or even a faulty panel (not repairable).
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 2 times, and see if there is any change in symptoms.