I have pretty strange problem. I have 2 monitors, Iiyama 2409HDS i E1900S, which are connected to the PC(Gigabyte GTX 460) with DVI cables. Both have been working without any problems for almost a year in this configuration. E1900S is treated as main monitor(it shows BIOS startup etc), 2409HDS as secondary(after OS loaded it starts to display something).
On sunday something strange happened. After starting the PC, I've noticed that the main monitor(E1900S), despite the fact that it's light is green(which means that monitor is on and is getting an input signal) did not show anything aside the first Motherboard welcome screen, despite the fact that the second monitor(which is treated as secondary monitor) is displaying everything normaly. OS is loaded corectly, I can do everything in OS normaly, which means it's running. It seems that I can even move my mouse to the other monitor, that my OS apperently recognises, otherwise I couldn't move my mouse outside of the boundries of the secondary display.
Now, if I only disable the signal to the main monitor(by Win+P shortcut), and I will enable it right afterwards, then the picture shows on the monitor and it behaves normaly untill I turn off my PC and turn it on the following day when the problem reapears. I also checked this morning if I can enter the BIOS. I can, I can also move around the options, but what's funnier is that after I left the BIOS and continued with system startup, the problem was gone and I could see everything normaly that follows (the OS choice screen, the system loading screen).
I have 16GB of RAM, XFX 550W power suply, the PC is practicaly new(bought at the beginning of this year). I disconnected and reconnected the DVI cables just in case, but no change.
Did some of you had similar problem, or could give me some hint of what could be the cause of this strange problem?