I'm feeling pretty desperate right now, I really hope someone can help me solve this problem.
Few weeks ago, I've put together my new computer using a Gigabyte ZA-97MX Gaming 5 Mobo. Since my GPU went broken the other day, I decided to use the iGPU (Intel HD 4600) of my i5-4690K instead. Everything worked fine with my monitor plugged into the DVI port and my TV plugged into the HDMI port. But suddenly the HDMI port stopped working over night. It disappeared completely from Windows and I'am neither able to enter the BIOS with my monitor connected to the HDMI port, which worked fine beforehand.
I also tried several cables and monitors and to reinstall the Intel HD drivers. I've even wiped the whole system partition but nothing helped. The BIOS is also the newest version available.
You will find my DxDiag attached to this post. If you look at the "Output type" line, it even says my monitor was connected via HDMI but it isn't! It's connected via DVI. Maybe this is a first hint?
Hope you can help me, I really don't want to send the mobo in for warranty which means I have to take apart the whole computer and wait for weeks.
If this was an onboard graphics problem or even drivers, you would be able to access BIOS connected via HDMI.
It appears to be an issue with HDMI port on the motherboard. I recommend checking with Gigabyte support for more information: http://www.gigabyte.com/support-downloads/support-downloads.aspx GIGABYTE - Support
thank you very much for your answer. I was hoping I could avoid disassembling the whole computer but there seems to be no other option. At least I now know that there is no issue with the CPU.