Self Build Post / Boot Issue

Rattlehead_ie

Hi guys,
Wondering if you can give me a little bit of a hand. Have self built machine just over a yr now, working perfectly up till now. Without me making any changes hardware wise (possible windows update) it now has started to not boot or post.
Symthoms :
Machine turns on, chasis, CPU and GPU fans startup.......... no beep and then chasis and I believe CPU fan increase RPMs and machine sits there.

Things Ive noticed :
My RAM which has LEDs will, after the fans initially startup, light up and LEDs will display load through RAM. - This is not happening.
I could stop and restart the machine 50 times and it may come to post and boot one out of the 50 if I am lucky.
If I leave the machine plugged out for a long period (12 - 18 hours) the machine seems to post and boot 1st time 98% of the time.

Troubleshooting steps taken:
This is not in a particular order but..
Mobo swapped out
RAM swapped out
GPU Swapped out
All peripherals inc HDDs plugged out
All chasis fans plugged out
PCI Wireless Card out

Comment:
You'll see from my spec below that Ive a ASUS P5E which I know has had some issues with RAM voltage etc and I am wondering if anyone can explain this to me and if there are settings in my BIOS I can look at to figure this out. Everything in there is set to auto at the moment. Also attached are the screenies of BIOS

SPEC:
ASUS P5E Socket 775
Intel Q6600 2.4GHz Go Step
Intel Q6600 2.4GHz Go Step
Ballistix Tracer 240-pin DIMM (with LEDs), DDR2 PC2-6400 memory module
BFG NVIDIA GeForce 8800 GTS OC 512MB PCIe 2.0
2 500gb sata
3 x 2.0 USB Devices
5 Case fans
Linksys WMP600n

gbee

Not too sure what you've done already, but it sounds like a classic case of heat shield failure.

If your heat shield or paste or both have dried out and become brittle you'll have insufficient heat transfer to the cooling system and fan.

Also another high suspect is the Power Supply.

Rattlehead_ie

Paste is all there and nice and gui so I dont think its that. Maybe the PSU then, Ill investigate that further. If anyone else has any other idea it would be great. Thanks

Overheal

Troubleshooting steps taken:
This is not in a particular order but..
RAM swapped out
GPU Swapped out
All peripherals inc HDDs plugged out
All chasis fans plugged out
PCI Wireless Card out

And you havent tried to reset the CMOS yet>?

cherryghost

yeah. reset the CMOS. it's pointing towards a fecked motherboard though. switch out the PSU if you can if resetting the CMOS does nothing

Overheal

Also your specs on the ram

Specs: DDR2 PC2-6400 • 4-4-4-12 • Unbuffered • NON-ECC • DDR2-800 • 2.0V • 256Meg x 64

the machine is not necessarily going to default to that - if you get back into the BIOS you want to make sure your ram is at the correct driving voltage and timing.

Rattlehead_ie

The CMOS has been reset multiple times and the CMOS battery replaced.
Sorry the most important swap out of all I didn't mention :facepalm:
The motherboard has been swapped out, although I am back using the original at the moment.

I believe its the PSU as it hasnt been swapped out and Im going ot have to look into that

VenomIreland

I had a problem like this with my first build, make sure the CPU power pins are plugged in.

Rattlehead_ie

Just an update guys,
I replaced the PSU over the weekend to a 750w Cosair and I am not on my 4th successful reboot so everything so far is looking good. Thanks for all the help and advice.