I tried the graphics card(HIS Radeon R7 260x) at a different computer with a different board and it works just fine. The PC with the Desktop Board DP55WB is equipped with a 630W Be Quiet power supply and is still running - with the old card, a Sapphire Radeon 5770 HD - without any problems. That's how I do it: Unplug the computer and turn of power supply. Disconnect the old card from the PCIe 6-pin power supply connector, take out the old card, put in the new card, connect it with the 6pin and plug on the PC and power supply again. Then nothing, no BIOS, no output, i tried hitting the F2 key to load BIOS and the F8 key to boot Windows 7 in safe mode, but it looks like the OS doesn't even boot. The cooling fan of the card is working and the display (an Acer K272HL) has to detect that there is something plugged in on the other side, coz if the display cable is not plugged in any device, the display message states "No cable connected" instead of what i get now "No Signal". Any suggestions?
Thanks for ur response. Been there, done that, and it works fine with my old card. Bios successfully updated, then reboot again. After that i installed the new graphics card and gave it a try. Now I have an ouput, but another big problem: PC holds at boot giving me 4 options "BIOS setting: " ; "BIOS Flash Update: " ; "Boot Menu: " and "Network Boot: " (The code where it holds next to the options is 5A). Unfortunately, it doesn't matter which key i press, nothing happens except a BEEP sound from the motherboard. How can I overcome this options? I read in another thread that u can try holding the power button until u get 3 short beeps to enter the power menu, but that can't work for me since every time i press the power button and hold it the machine turns off / back on / off / back on and so forth. It just cannot be held i guess. What should I do now?