It is very possible that the old TV had a separate antenna socket and the new one does not. Unless you gave a new cable and it has a short circuit. I don't see any other reasons. Well, unless there are some power leakages with this new TV, but it's unlikely. Make a test and briefly shorten the pin and screen in the TV plug on the cable. When the diode turns off, it means that you do not have a separator in the system and this TV set will cause such an effect. I note that there is a minimal risk of burning the power supply during this attempt, but if the TV also goes out, it means that it can withstand.