can't use two hdmi ports on two TVs

[pasifil]

hi,
i tried to connect my laptop (windows 10) to the hdmi ports (seperatly) and it works ok (everything was tested on two TVs), except when one hdmi port is already occupied by a TV box (the channels provider) and then i get one hdmi connection working and "no signal" on the seconed port. it's like i can't use the two hdmi ports together, even though when only one device connected it's fine - again, tested on both TVs, so i guess it's not a problem with the tv's hdmi ports.
thanks

 

[americanaudiophile]

I don't see why the other HDMI Input being used should matter but it's easy to try changing the order you boot the laptop and select the HDMI input that it's connected to.
Can you check if both HDMI inputs work with the TV box and another source other than your laptop are connected to the same TV? That will tell you if there is something weird in the laptop HDMI output.
A work around would be to use an external HDMI input selector.

 

[pasifil]

I don't see why the other HDMI Input being used should matter but it's easy to try changing the order you boot the laptop and select the HDMI input that it's connected to.
Can you check if both HDMI inputs work with the TV box and another source other than your laptop are connected to the same TV? That will tell you if there is something weird in the laptop HDMI output.
A work around would be to use an external HDMI input selector.

thank you for your answer, i tried to change the order I boot and it worked on one TV (tried to connect the laptop and a different android tv box).
Then I tried the same on the seconed TV. it didn't recognize the laptop. it recognized the android tv box but the screen kept blinking. Both HDMI ports works ok when one device is connected, but when two devices are connected it shows only one (or the screen blinks). I guess it's a problem with the TV?

What kind of perfences should the HDMI input selector have?