W520 shuts off intermittently, no BSOD or shut down

[xhu12]

BTW I monitor my temperatures very closely, when the mysterious shut down happened, the temp was around 30/40C so the temperature is definitely not the issue in my case.

[boeing82]

Good to know--figured that wasn't the problem.  Try the Memory Diagnostic test.

[xhu12]

Hi, so you mean the 4GB ram was broken? or they replaced it with a different setting, i.e. 2 X 2GB in 2 slots instead of 1 4GB in one slot?

[boeing82]

The actual RAM hardware was faulty.  They replaced all four of my 4GB RAM chips with new ones, and the problem was solved.  If they're able to determine that only one of your RAM chips is faulty, I'm sure they'd only replace that one.

[xhu12]

Thanks! That reminds me I just recsently added 4GB myself to the laptop, I wonder weather that is the reason for that, I am pretty sure that I started to realize the problem after adding the extra 4GB block, maybe I should take it out and see whether it will solve the problem or not.

[ColonelONeill]

Faulty RAM would crash the integrated GPU in an Optimus configuration, which is why it would work in Safe Mode and Ubuntu.

[Beto]

It may sound stupid but my W520 shut several time (slowly) off because on Windows Power Options --> Change plan settings --> Change advanced power settings --> Hard Disk ---> Turn off hard disk after:

there was the setting to turn off after 15 min. I laughed, when I figured out that this setting set my computer to sleep 

[xhu12]

Ok, I ran all kinds of different memory diagnostic tools, but nothing showed any error/warning, the memory seems to be fine. I suspect that is related to some complicated power saving issues... since I only had this random swtich-offs when my computer is not under load so far.

[boeing82]

Interesting.  Try burning an Ubuntu boot disk (not installing it) and run from that and see if it happens.

[xhu12]

I actually ran ubuntu on my w520 for about a week but had to remove it because the kernel doesn't have the proper hardware support, especially for the i7 sandy bridge CPU. There is no driver availble and thus all CPUs ran with 2.2 GHz all the time even in idle, and drain the battery like crazy. Also the fan control didn't work properly either, I had the impression it remains the same speed of about 3300 RPM and will increase speed only if the CPU temperature reaches nearly 70C, so I removed the ubuntu and now runing ubuntu as a virtual machine under windows 7. But I didn't have any crashes under ubuntu, so I suspect the reason therefore is because ubuntu was unable do use all these energy saving features. Well I guess I will wait and see how often it will happen in the future, if it happens often,then I will send it to the repair facilty and see what they what happens next.