Again no signal :(

[deny999s]

here my situation, i build a system about 2 years ago, and decided to do clean up yesterday;
* mobo : asus rampage ii extreme
cpu : intel core i7 920
ram : 6 x 2GB corssair dominator (blue)
hdd : intel 80GB SSD
hdd2 : WD caviar black 1TB
gpu : evga gtx 480 sc
psu : cossair 1000watt modular
radiator : koolance with 3 fan
pump : pmp450s koolance
all other cooling component : koolance
optic : LG Bluray RW
monitor : alienware 23" 3D monitor
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after clean up all the part from dust all day yesterday, and this morning i put everything together back and push the power button,
1st time : fail to turn on , followed by searching google and other section trying find the solution, by removing 24pin and 8 pin power cable and wait for 15mins.
2nd time : fan on, weter pump on, HDD on, every things on, connected to the screen and actually booting the OS and to the login screen, since all cable and other part still so mess and not in the case, i shut the computer off again, and then put everything back nicely and neat in the case and close the both side panel. then...
3nd time : fan on, water pump on, HDD on, every things on, but it last for 6 sec exactly, and it shut off , and next 1 second it turn back on and everything run smoothly, but my monitor post theres no signal from computer...
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im stuck really, can't figure out whats wrong with this computer, I'm sure psu, gpu, cpu, ram, and hdd work fine like 20mins ago before i shut it off and tie all the cable and fill up the water tank. i try remove the bios battery and unplug all cable and wait for 10-20 mins, and put it back all again and it turn on normally but still no signal...

 

[87ninefiveone]

If you removed your memory or CPU try reseating them. Also make sure your GPU is firmly seated, all of these can cause this issue assuming you didn't fry something during the cleaning.

Assuming your getting no POST beep codes as is, if reseating things doesn't work unplug everything and start pluggin items back in one at a time until it stops working right again, make sure you have a system speaker plugged in and do it in this order....

1. Bare motherboard and CPU with power connections only. System speaker should beep indicating a memory error.
2. Add memory one stick at a time performing a boot in between each addition. Any system beep codes?
3. Add GPU. Any system beep codes?
4. Attach storage devices (HDD, SSD) one at a time. Check for beep codes between each one.