I have a machine with an ASUS M4A89GTD PRO motherboard and integrated Radeon HD 4290 GPU. It has an AMD Phenom X2 555 Processor. I had Windows 7, and upgraded to Windows 10, then changed my old monitor to one fed by an HDMI cable. Now when I turn on the computer nothing happens - no POST beep, no Windows. But if I reboot, everything is OK, and it loads normally. Any suggestions?