Pc don't want to start, no error msgs just black screen

[6thSense]

Hello guys, I decided to revive an old pc so my brother can use it before uni. The pc itself has been in storage for about 2 years, because it stopped booting up and nothing was showing on the screen.

The pc WAS with 775 intel e5200 cpu 2x2GB hyper x Ddr2 ram, radeon 4850 512mb sapphire graphics, p31 es3g mobo and fortron sàga 350w psu. Nothing was showing on screen when you press the button to turn it on, only the fans are spinning. 

Last week i bought a new motherboard- Asus 5w deluxe and q6600cpu. Assembled everything but i have the exact aame symptoms, i get error beeps only when i remove the ram. The gpu is working,because i tested it on my other rig. I gave power to the gpu while on the problematic rig because i thought that something might be wrong with that but no luck. I was trying to boot it up with one of the 2 ram sticks, swapping them from time to time. The problem still exists, as if i didnt plug the monitor. Oh and the fans stops working after like 1 minute.

At this point i am out of ideas what the problem might be. 

Any thoughts on this are appreciated! Thank you!

[Slottr]

Are you plugging video cables into the motherboard or graphics card

[6thSense]

The video card, I dont have vga on the motherboard. Ive tried to frankenstein start it once last night. I plugged my trusty r9 290 into this rig ans gave just the gpu power frim my other pc cuz im pretty sure the fortron cant handle that card at all and i switched both pcs on. Still no sign of any video signal...

[Gunn]

Maybe you are using a unsuported ram mhz on that motherboard or the ram is dead 

[6thSense]

I am using regular ddr2 800 ram, nothig too fancy. If it was unsupported, why the old p31 mb have the same problem? i dont thin both sticks are faulty, but if i locate ddr2 ram imma try it