I'm facing a kind of a mysterious problem.
We have a PC with Debian 8 installed. It boots fine and works well, unless I try to boot it wihout a display. So, I shutdown the PC, unplug display and then boot the PC again. After that I try to plug the display on and nothing happens - display not working, it just shows the "No signal detected" message.
But that's not all of the mystery: if I boot the PC without a display, its network card also does not get started. Yes, without a display, the network card is not working. If I try to plug a display after the PC has booted, network card and display are not working either. If I boot the PC with a display plugged, both display and network card are working. If I unplg the display after the OS has started, the network card continues to work and once I plug the display back, it also works.
We actually have a set of identical PCs (entirely identical) and they all have the same behavior. I've installed Windows on one of them, the problem has gone, no matter when I plug a display, everything works fine.
What have I done:
- installed CentOS 6 - still no luck
- removed acpid from CentOS - no luck
- disabled acpi entirely using this tutorial - apparently, no luck.
Display is connected with a DVI port, if that matters.
Have anyone faced the same problem?