A long time ago, my PC suddenly started freezing randomly; it would even freeze at RAM tests, so I took it to a trusted technician thinking he would change RAM memory and tell me that everything was OK. I took my PC to this guy two times (in order to make this story simple), first time he didn’t even notice the issue: he made some tests and he returned my PC in a perfect state (the issue was gone for some months); the second time he didn’t see anything neither, but he decided to test another RAM memory stick with my motherboard (everything went OK) and when he was about to return it again, he saw the freezing, and again, after some other test, I got the PC back running normally (this last time he changed RAM stick from DIMM slot).
Obviosly, the freezes came back and I have been for two years now trying to figure out what the heck is happening. I have played a lot with BIOS settings (not BIOS Setup settings, NVRAM “hidden” settings) activating and deactivating things. I have also updated firmware.
Some incorrect info is being stored somewhere, and it cannot be removed by erasing BIOS chip. In my opinion, this could be related to intel ME/AMT because I’ve had some “tests” through which I have managed to solve this issue by a little time (one day or even a month and a half, to the point that I thought it was completely solved). Sometimes, when I disable Onboard LAN Contoller (by writings 0s to its PCI config space) and intel ME in a specific order, in addition to enabling a PEG port (that way, the LAN controller bus in PCI changes (Bus:Device:Function) from 01 to 02), the issue goes away by a little time (I don’t know why, but this method only works sometimes). I must disable LAN through PCI, if it is done through BIOS options, the issue persists.
I think LAN could play an important role to understand the issue: the “working” LAN controller is referenced as “Onboard LAN controller” in BIOS options (an external device) and even though there is a “PCH LAN” BIOS option, I don’t see anything when I enable it (Could it be that there is a motherboard conflict between these two controllers, or is it that simply PCH LAN is not present on my motherboard). I think that Wake on LAN (WoL) could be key to this issue: it requires intel ME and LAN connection.
Wake on LAN (WoL) must be managed through intel AMT as intel ME is the only running system which could wake up the PC, and Windows can configure LAN to enable or disable PC waking up due to magic packet (and the ME interface to system OS is intel AMT)
It would be very helpful to know how Wake on LAN (WoL) works. If intel AMT manages it, then it means that PCI interface is not turned off when PC is shutted down (as I’m using “Onboard LAN controller”). Another option is that LAN controller is keeping information and it is in charge of sending signals and orders to the ME so that the computer wakes up.
I haven’t tryed to disable Wake on LAN (WoL) in BIOS options, as I don’t live in my house and I have had this idea in the present week
I know about computers, so the idea of LAN controller managing itself as an independent system is really weird for me, so the intel AMT option makes more sense… BUT as I said, I updated SPI chip (Flash descriptor + BIOS region + ME region), and if any data was wrong, I would have corrected it through these updates.
As you see, nothing makes sense…
EDIT
I just remebered that when I did that LAN disablement thing for a month and a half I also disabled ME DID Message and one day when I booted to Windows I found that TPM device was showing a warning symbol and a new PCI device for debugging was showing at device manager (Intel North Peak - 00:1f:07 (Bus:Device:Function)). Now, every time I boot with ME DID Message disabled I find that Intel North Peak device, and this hasn’t changed with any new flashed BIOS. This could provide a clue about where is this “information which doesn’t get erased even after an SPI ROM chip flash”