Z77-DS3H - onboard graphic not working; 16 GB installed only 8GB enabled - HELP!

[lesta]

Please help with this issue. It is driving me mad! 

I have a GA Z77-DS3H mobo with BIOS version F9. The CPU is an Intel Core i7 3770 3.4GHz with the stock fan, and memory is Corsair 16GB (4x4GB) DDR3 1600Mhz Vengeance "low Profile" Memory Kit CL9 1.5V.

The problem is that inexplicably the machine will fail to boot unless I have a PCIe GPU inserted. When I insert a GPU, the system will then boot, but tell me there was an error with my BIOS configuration. When I enter BIOS the only thing I can find wrong is that the BIOS reports that there is 16GB installed but tells me only 8GB is enabled.

If I then boot to Windows (7, x64), it reports that only 8GB is in use, but if I run Speccy (from piriform.com) it reports the same as the BIOS.

How can I get the PC to use the onboard graphics and utilize all 16GB of my RAM?

Previously, I read that this can happen if the CPU fan is not seated correctly, but I have checked and it is fine (loosened it, tightened again; checked all fasteners are correctly fastened)

thank you for any advice,

Lesta

[lesta]

Forgot to mention that everything is running at stock speeds. I have no interest in overclocking!

[AleR]

Use aida64 or cpu-z to identify - is your PC(CPU) see 2 or 4 memory modules.
Try to swap modules and check again what memory slots or modules don`t work
Probably you have bent pins in the CPU socket.

[Del]

It would seen that "Corsair 16GB (4x4GB) DDR3 1600Mhz Vengeance "low Profile" Memory Kit CL9 1.5V" is for Gen2 not Gen3 Systems..

Change RAM.

EDIT: From Corsiar site "1.5V Vengeance Low Profile DDR3 memory is designed to meet the memory specification of the 2nd Generation Intel® Core™ processor family. "

[lesta]

All the RAM modules are working.

The problem, as far as I can tell, and possibly one supported by a post I found elsewhere, is due to poor contact between the CPU and the pins on the motherboard. Someone reported similar problems, and he found that reseating the heaksink helped.

I have done this, too, but to no avail, but I think the problem lies with temperature... when the PC is warn, all memory is enabled. When it is cold, only half is enabled. So, I can only imagine that overnight, when it gets very cold in the PC room (it's north facing, and not well heated) there is some mobo shrinkage that is leading to poor contacts.

After posting my original message, everything suddenly started working properly, and remained so until a period of no use, when the problem returned.

Curious.

My old mobo would fail to recognise the hard drives in very cold weather.

Shrinkage is something that Gigabyte could possible look at?

[lesta]

Just done some more testing...

• Removed heatsink and CPU to check for bent pins - all pins OK
  Reseated CPU and heatsink - no change to the problem
  Tested memory - bank 1+2, then 1+3, 2+4, and 3+4 - each bank help a 4GB memory module. In each case the entire 8GB was correctly enable.

This tells me that both memory channels are working. However, as soon as all banks are populated only banks 1+2 are enabled.

I would expect that is there were bent pins, then my testing would have shown with memory bank were affected.

So there is something weird going on here. Also, I did clear the bios and loaded default values, all to no avail.

There has to be a solution to this. Anyone?

[lesta]

CPU screenshots, FWIW...

[lesta]

Anybody? 

From searching it appears this is not an uncommon problem with the Z77 chipset. It seems bizarre to me that - if a pin were bent - everything should work perfectly or 4 months. Do pins mysteriously bend themselves out of alignment? If so, there is a manufacturing/QA problem that needs sorting!

Something else I have noticed, after a period of non-uses (three or 4 days) when booting, I receive a message that the BIOS has been misconfigured. Yet the BIOS is just as Gigabyte set it. I don't generally tweak.

[absic]

Have you tried the F10f Beta BIOS? If not it might be worthwhile updating to it and seeing if that helps. If there is no improvement you can always flash back to the F9 if you want to.

With onboard graphics I had a problem when I first installed my Z77 mobo which I resolved by:
Reflashing BIOS using QFlash
Shutting down PC immediately the flashing process had completed.
Removing add on GPU Card
Connecting monitor lead to onboard graphics port (DVI)
When I restarted the PC the onboard graphics were running and I was able to reinstall my GPU later on without a problem.

[lesta]

Thank you, Absic,

I will give that a try. I has noticed that a beta of F10 was available but have avoided using beta firmware so far. But I will give it a try.

Incidentally, I has reflashed the board with F9, but this made no difference. I will report back once I have finished examining a macro photo of the pins to see if I have bent a pin.

Lesta

[lesta]

[Applauded]

Absic,

I took time to demonstrate to my wife the bizarre nature of this problem. Swapping RAM modules, using every permutation I could to show that a maximum 8GB was only ever enabled.

And then I flashed the BIOS with F10f (from Windows 7 using @BIOS).

There was a pleasant new Boot screen upon restarting, and...

...16GB of RAM is now available again!

So, possibly it was a problem with F9. If the problem returns, I'll let you know. (And by the way, it's very cold in the computer room again!)

Thank for the suggestion.

Lesta