What would be the manufacturer name and model of the mentioned Box PC? And what is the mentioned up-to-date version of the video driver you have installed? Please provide detailed information on what has been required in order to properly assist you.
Concerning the connection of the TV, we would require you to test with a straight connection with no other device in between (no adapter, converter or KVM)
The mainboard is an MI956 Mini ITX from IBASE.The driver version is 22.214.171.12437. But i have seen the same behavior on another system with the same graphics driver.
I connected the PC with an DVI monitor. No adapter, only one normal DVI cable. Then i plugged it off, wait a few seconds and plugged it in again. Same result, the graphic output changes to "Build-In Display" and stays there. The only thing which is different is the HotKey to activate the DVI monitor: Strg-Alt-F4 instead of Strg-Alt-F1.
What I need is only one thing: The graphic adapter has to activate the signal to DVI-I in any case. If there is a cable connected or not (at booting or in operation mode) - the output has to go to the DVI-I.
Have you tested with the 126.96.36.19921 version that was provided by IBASE on their web site?
It is listed as Intel Core i3/i5/i7 Graphics Driver (Win 2K & XP)
Did you try using another operating system such as Microsoft* Windows* 7 or Microsoft* Windows* 8?
In the other hand, I have the feeling that this might be related to how the Video BIOS in the system reacts to that hardware change and having the integrated display as always active, however I have to research and confirm this.