第四台信號問題。 Learn how to fix poor picture quality issues including pixelation (像素化 成像化) with these troubleshooting tips. Pixelation (squares) observed on the screen represent packets of data which have not been received or were lost in transmission due to a poor connection. (信號在傳輸的時候有失去信號資料) This is an indicator of a poor signal (信號不良) which can be caused by a variety of issues including damaged coaxial cables (傳輸線損壞), loose connections (線材連接鬆脫), faulty splitters (不良的信號分配器) and more.