Help! My new pc won't start

Hello!

Today, I got my components for my pc. Everything went smoothly, I installed all the parts, mobo, cpu, gfx, etc etc etc. Until. I ran to a problem when I started the pc. The problem is, when I start the pc, all the fans start spin and all, then it stays on for 5-6 seconds and 'shutsdown' and does this weird sound, not a beep, more like a like somekind of a "malfucntion" if you could say that. Then all the fans shutdown and everything, then it stays shutdown for 3-4 seconds and restarts itself. After that it runs like it should be. Except, the system led isnt now on, its only on when you press the dvd-drive button to eject a cd.

Another thing to this problem is, the pc is connected to a 24'' BenQ display and it says "No Signal detected" And I've tested the monitor on a another pc and it works well.

Specs are here:

PSU: Corsair 550W
Mobo: Asus P5Q Pro
Gfx: Sapphire HD4780
Cpu: Intel Q9450 & Noctua NH-U12P
Ram: 2 x 2 gb Kingston 800 mhz
Harddrive: 750 gb Western Digital
Case: Antec Three Hundred

Thanks for advance!

 

the monitor probably has nothing to do with your problem, thats just how it looks cause it's actually not getting a signal til the computer fires up correctly...could be overheating, incorrect memory, or maybe even a bad component...can you check all the connections, re-seat the ram, make sure the cpu fan/heatsink is properly in place, and double and triple check everything, especially the parts where the hdd led, power led, usb etc connect to the motherboard (it's very common for those to either be labeled wrong or erroneously connected)

 

Okay. I've tried taking everything off and then putting it all back together. And here's the result. The comp now doesn't restart after the 5 seconds. Vola \o/

But... It still doesn't make any signal to the display. And the HD4870 all three(of four) leds (1601, 1602, 1603) are lightened up. And if I remember correctly, they meant, A power cable not connected, B power cable not connected and its overheating. Am I correct?

Well, anyways. The fan of the gfx card doesn't spin like a 5-year old in a sugar rush anymore IF I put the memory thingie to slot A1. But when I put it in slot B1, damn, it's high on sugar. So I putted both memory stickies to A1 and A2 slots and the fan spins normally. Everything sounds really normal, just that no image on display and the three leds lighten up. Even HDD sounds like its trying to process it.

So I've come to an solution in my small head. Or not. That the fault is in the gfx card? Not in the mobo. Cause the mobo seems to be working? I would assume, I don't know tho.. Im just a "newbie" in these kind of things.

Anyone wiser than me would show me the way?

 

Imho a 550w PSU is about the lowest you can go with a 4870. Do you have another PSU you can try? If not I would be seriously looking at not enough power getting through.