Your TV is going into protect mode because something has failed, you need to get it fixed, without the correct tools or equipment you cant do anything to this yourself.
First off its highly unlikely that with this pioneer set you will know what we tell you to do UNLESS youve had some electronics training as these sets are monsters within them selfs when it comes to repairing them. But one good thing is Most pioneers set mostly the projection sets that have that fine cherry wood finish on them as well as the walnut types all have replaceable boards as thats how pioneerr sells them as repairable in house .But you gotta know what pcb to replace as some problems with these sets can have two to three PCB's to replace at once and if you dont Know and replace the wrong ones you have to start from scratch .If you dont have a clue about The set call pioneer as they still do have authorized peeps to repair there sets and if you feel its way to expensive for such an expensive set you bought as most repairers these days gotta make a living but pioneer will most likly work with ya.