Technicians Came Today Replaced With Another STB (3rd Transfer Box for me) and said the problem may be HDMI.
They said that my TV is leaving some leaking current to STB through HDMI cable ..
Tv's use AC current while STB use DC current the AC current of Tv is going to STB which leads to IC damage in STB.
He later said to use the TV with RCA connnector (those Yellow Red White SD connection cable) for some days so that we can rectify the problem and check if HDMI is culprit, which means No HD channels ?