I have a problem with a home built HTPC. When I power on the computer, it emits no beeps and there is nothing on the screen; All the fans start (sys fans, cpu, video card). I can also hear the HDD work and emit a small sound just after powering on. Then I have to turn off the power supply switch to shutdown. Pressing the power switch on the case does not work (holding it does not work either).
I connect my tv (1080p hdtv) to the computer using a hdmi cable. Also, I couldn't find any internal speaker connection to the case.
Ok I went through the check list and everything looks good.
However, yesterday i found out that my video card had one of its red led ON. Its the d1601 over temp protect led. After googling a bit, some people had this issue because of bad PSU. I tried plugging another pci-e cable from my psu but got no success. Everything seems to be correctly plugged.
I did some Googling myself and I would narrow it do to either a bad PSU or GPU. Are both of them new or are they used? Can you try both in another PC one at a time to see if one works & one doesn't?
I'm leading toward a bad GPU, since lights and hard drive starts up but I can't rule out the PSU based on your original information provided. Your best option is to test components in another PC or RMA both for good components.
If someone else has any ideas, hopefully they can provide it.