I'm having a similar issue. If I change something in the BIOS on my Motherboard like a frequency or timing then save and exit my monitor 95% of the time fails to detect either a DP or HDMI signal. All i see is the monitor LED fluctuate between orange and white thus leaving me with a brick. By hooking up another monitor which works perfectly I can get the XENEON to work properly until the next time I change the BIOS.
Do you see on the monitor when booting a no signal message?