Crosshair III 790FX System Post Diagnosis

belial8321

belial8321

belial8321

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Joined
25 Jan 2011
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757
Location
Solihull, Birmingham
Ok, hey guys, this may end up as a bit of an essay, for the past month now i have been trying to work out why my pc has so much problem posting, 99% of the time nothing happens, not even a post check, here are the steps i have taken so far.

Parts all out of case on a non conductive and static free surface -

Motherboard (Crosshair III 790FX RoG)
CPU - AMD Phenom II x6 1055t
PSU - OCZ Stealthstream 600watt
RAM - Corsair XMS3 4GB 1600mhz

I try to power on system with this setup, CPU fan comes to life, hard drive light on mobo flashes, RoG icon on mobo is lit up and psu is active with fan spinning, LCD poster simply says "welcome" for a few seconds then starts to display the unconfigured Cmos time starting from 00.00.00

I try this again with just one stick of ram, same thing happens, then i try again with no ram at all, expecting a pc beep and a warning from poster, the same thing happens again - this leads me to believe that its not my ram that is dysfunctional as it is not even trying to detect it in the post

I know for a fact that this mobo will post happily if all the "power leds" on mobo are lit, there are about 4 as far as i can remember, which light up green by key component areas, RAM, CPU, NB, SB etc, but at the moment no lights are displaying.

I first thought when i got this problem it was a lack of power, my Radeon 6970 could have been hogging it all, but even without card still nothing, and card is tested and working in another system.

The problem is i cannot test my other components as i dont have anything of their level to swap out with, My cpu i am pretty confident is perfectly ok, video card is fine, ram - im not too sure about as i have had some problems with it (lcd poster - DET DRAM) - sticking at this stage of post)

The power supply, according to all psu calculators is more than enough for this system and is reliable and works with other systems i have tried

This, to me, points at the problem being the motherboard - somehow it isn't recieving the power it requires to start posting, why? i don't know but i would be very greatful if anyone could help me shed some light on this and offer their opinions, TIA,

Jamie
 
Erm not too sure, its black with blue leds? XD it has worked before, it was working earlier too,

I forgot to mention that each time the psu is turned off for 30 sec or more i can't boot it again, like i can spend hours then finally get it to boot, it runs fine then for up to 40 hours, then when i turn it off at psu, and turn psu back on 30 sec later thats when i get this problem, i have an OCuK 850watt psu as well, same problem with that, so i dont think psu is problem
 
is it overclocked?

wonder if its a type of cold boot issue you have here.

or if the signal to tell the psu to turn on from when the power button is pressed is playing up, dodgy connection
 
It normally is yes, but i have reset the cmos many times in attempt to make it post, my overclock profile is saved and stable
 
so unusual, i reseated cpu with a stock heatsink with no ram, periperhals or video card and it boots and power lights come on wtf?
 
yeah it beeped when it didnt detect ram or video card, i seated ram and tried old video card, it booted fine :O i just tried to swap in my 6970 for the old 2900XT and now its doing the same thing again :( am gonna try reseat cpu again and boot with 6970
 
ok i did the same thing again, removed cpu and ram and card, booted with nothing in mobo and nothing happened, power off, reseated cpu, booted and it beeps, power lights on mobo, boot with ram and video card, all checks complete, thru to cmos to reapply overclock, have turned off psu to see if it still boots after a little time powered down
 
Ok im back on the pc now :o running a linx stress test on it, if it gets through 20 passes using all ram and cpu its stable as far as the overclock is concerned isnt it?
 
Depends on how rigorous you want to be. I wouldn't say it was stable until you can simultaneously Prime95 blend, Linx 20 passes on max and let prime run for 8hrs+.
 
I see your reasoning :p though with my main games being CoD mw2 and wow im not gonna make my cpu and ram sit at 100% all the time though :P
 
Sounds like it could be memory issues.

Try and reseat it if you've not done so already.

Otherwise try each stick on there own to see if that makes any difference.

Also check that the voltage is set correctly in the bios for your memory.
 
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