Yes, to answer from prev. thread, I pulled out the dedicated graphics card. MB vid still didn’t work (both VGA and HDMI).
Does the alternate HD need an OS to get far enough for the BIOS to kick in?
Oh, BTW, since there’s no initial video, in that time frame I doubt the CPU gets hot enough to be an issue. There’s a massive (for PC’s) liquid cooled heat sink on the CPU...
If you have NO video at all, and your monitor is OK, then it is most likely a motherboard issue, RAM or CPU. The one thing you can try is removing all but one of the RAM cards, if that does not work, swap it with another. If the motherboard has a speaker, listen for beeps. It may also have some LEDs for the POST (Power On self-test). Search the make and model of the motherboard for a troubleshooting guide. I hope this helps.