As this is a mini-ITX board, is there any chance its gotten too hot or dust has built up inside the case? I'm not sure about the D at the end of the model name as all I could find was the product with this support page: http://www.intel.com/p/en_US/support/highlights/dsktpboards/d945gclf2 - is that your board?
You could run the no-boot troubleshooting wizard (a link is on the above page) if the case is clean and dust free throughout. What do you think may have brought on this problem - have you made any system changes? When you boot it can you press F2 during POST and get into the BIOS setup screen? Maybe it's just your MBR is corrupted and needs repair (especially if testing with a blank HDD connected and the original disconnected allows you to perform a complete 'test OS install').
Hello, thanks for answering!
First of all yes, this is my motherboard. The extra D is silkscreened on it, I guess it's not needed...
The system was running in a dust-free and ventilated area, with a huge fan blowing air at it , it had a very minimal amount of dust and the chances it fried from heat are almost zero.
This boot problem is not related to HDDs or MBR. The board simply cannot start. It powers on and gets stuck on a blank screen. There are no BIOS messages and keyboard/mice simply do not work. HDD attached or not makes no difference. It's purely a hardware problem.
I will check the no-boot guide in case there is some info but I think the mobo just fried.
Sorry about the long time getting back. Motherboards don't tend to 'just fry' themselves, there's always a cause. If heat isn't a significant contributing factor, maybe the board has suffered damage due to a power surge - perhaps after a lightning storm in the area. As you've already tried a replacement PSU (a known good one fully compatible with the board?), and the board is clean then all I can think of doing is a full strip down and inspection then test out of the chassis.