Samsung TV UE65mu6120k fault

Appologies , i did write it in earlier. the tv screen started to flicker only on one side. the colour stayed the same but the light flickered. So i bought a new Tcon board off of ebay and fitted it. it made it better but we still had the problem. the problem we also noted would stop if you moved the tv. as if it has a loose or broken wire. Next i purchased a power supply board from ebay and fitted it. this made the screen worse. the flickering turned into full negative colours and black out. the screen couldnt be watched. no amount of wedging would work. i removed the power supply and fitted the original. the screen would not turn on. it has power but will not start up. i opened the back to check the voltages . the screen from behind is lighting up white. i have checked the power coming in. ive checked the power to the tcon board. ive checked the power to the supply to the screen and they are all fine. the screen just wont work. what shall i test next? any suggestions on what to try now would be greatly apreciated. thank you