WORKS ON ONE TV BUT NOT IN THE OTHER PLEASE HELP

I have a MAG 424 two Sharp TV, the box works I one TV but on the other the first screen comes up as when you plug for the first time and then goes into a black screen and that's it, any ideas?

*I have removed all the HDMI cables unplug the TV and hold the power button for more than 30 secs.

• I have done a factory reset on the TV and nothing

• I have try different HDMI INPUTS on the TV with different cables and nothing.

• Tried different video resolutions in the MAG BOX and nothing

• Gave the box to a friend to try at his place and it works fine.

Any ideas how to solve this issue?

Thank you in advance