unpredictable shutdowns on T420i

[alefried]

Hello,

I have an annoying issue with my T420i, that randomly shutdown while working, on my ubuntu 13.04.
no matter i am on AC only, or on battery, or both.

I've tracked temperature evolution while working, and it does not seem to overheat...
I have performed memtest, HDD verification and video memory test, without finding any issue using ultimatebootcd. Interestingly, i did not encounter any issue while performing these long tests, so i started to hope again !

So i decided to format everything, restart from zero and install debian wheezy. it was stable with minimal distrib (only cli) and openbox, but i encountered a shutdown few minutes after starting gnome3...

Also, i noticed that some key combinations are awkward, such as Fn+o that make it sleep, or CTRL+ALT+left, that shut it down ... even under minimal-cli debian. Also on Ubuntu, the wireless connexion tended to disrupt from times to times, and all these strange behaviors started more or less together ... If it ever rings a bell for you

Do you have ideas about what i could test to identify my problem ? Could it be a mere keyboard issue, that randomly sends 'shutdown' signals ? Could it be a problem with another hardware element, what could it be, and how could i diagnose ? Would it be worth to explore some advanced BIOS settings, or to update it ?

As you can see, i am a bit lost with this, but having formatted everything, i am ready to explore all the options !

Thank you !
A.

[agarza]

Can you troubleshoot using a Windows Live CD and using it for several hours to see if the same behaviour is still there?

[alefried]

Hello,
I have wiped the hdd, and reinstalled the original win7 system using initial recovery dvd's.
Then i have updated the bios, but still, the Fn and alt keys keep triggering sleep or shutdown.

Actually, the topic could be renamed, because the shutdowns are indeed predictable, and occur when i press these keys.
I have booted on live distribution knoppix, and observed the same behaviour, so i do not know what it can be appart from a physical problem with my keyboard...?

I read somewhere that it could be due to a problem with the connector or with its wire (that could be in contact with some other internal electronic element) , so i dismounted the keyboard, checked the connector and tested a session with the keyboard dismounted, and observed again the same symptoms.

With an external usb keyboard, it is fine, so really, i think that my keyboard has to be replaced, isn't it ?