To directly answer your confusing title
From plasma.com:
Maxent is Sampo, There seems to be a rumor spreading around that maxents are actually Panasonic panels. These seems extremely unlikely as Panasonic cannot keep up with there own requirement. We suspect that maxents are actually LG glass with their own electronics.
Without more information, it is difficult to help out. If it is on all sources, you probably have a bad board internally. If it is limited to one input, it could either be your source, or that input's board. Either way, you're probably looking at a service call from a local shop. It appears they stopped producing TVs sometime around 2006, and parts will likely be unavailable, or very pricey.