Problem DescriptionZenbook Prime ( UX31A) users may notice the computer occasionally turning off without warning. The shutdown is unexpected, sudden, and there is no blue screen / stop code in Windows.
Users will find an event similar to the following in the Windows event log:
Log Name: SystemThis is a common problem with Zenbook Primes, and it has been for months. There is no software that can bypass the Windows shutdown process. The unit is losing power suddenly. ASUS has not found a solution, and I doubt that they are trying all that hard.
Date: 9/26/2012 12:10:38 PM
Event ID: 41
Task Category: (63)
The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.
This happens whether the battery is charged, and whether it is plugged in or not. It is rare (my machine did it once in two weeks).
Notably, on a previous UX31A (this is my second; I returned the first on account of this problem), it did it twice in two weeks. So I bought two separate UX31A’s, both with the problem. What are the odds? Quite good, if it is a universal, systematic problem, which I suspect that it is.
Specific ObservationsI have consistently noticed that the problem (twice on the other UX31A, once on this one), happens within about 5 minutes of waking from sleep. This one happened at pretty much exactly 4 minutes after waking.
The previous system shutdown at 11:47:44 AM on 9/26/2012 was unexpected.This, I think, is telling. I suspect it has to do with power regulation coming out of sleep.
The system resumed from sleep at: 9/26/2012 11:43:45 AM
Attempted WorkaroundThe Ubuntu guys have said this about sudden shutdowns - "RC6 on and Intel IOMMU off."
Status: Specific issue noted above may be safely ignored.I have disabled VT-d in the BIOS, along with Intel’s shutdown power management. I have not yet seen the shutdown problem. Note that you don’t need VT-d, as it is a virtualization technology, and it is doubtful that most people will use that on an ultrabook with 4GB of RAM.
Intel RC6 causes sudden shutdowns (Solved)Kernel developers are aware and working on an issue with DMAR+RC6.
However, Zenbboks experience sudden shutdowns with RC6 on and Intel IOMMU off.
The most stable configuration is to enable semaphores and turn off VTd in BIOS, see above.
However, this needs to be properly fixed in the kernel once RC6 gets enabled by default.
Zenbook users who have the shutdown problem – please try this, and let me know in the comments if you still see the shutdown problem.
AddendumHonestly, ASUS should have a public statement on their website indicating that it is a known problem, and explaining that they are working to fix it. Their boast of reliability is quite questionable at this point. That, and their service is just wretched. Their website doesn’t work well, their live chat doesn’t work at all (for me), they take too long to reply, and an RMA will take your laptop away for weeks on end. It really is unacceptable. But ASUS doesn’t ‘get it’, and that’s why they keep doing this.
This expresses the issue well:
My overall conclusions with this experience are that if I need customer service, calling the telephone service line is my best bet to get adequate and prompt help. Apparently customer service representatives must go through a list of set actions (resulting in multiple callbacks) before an RMA will be issued. Any sort of online technical support (e-mail or chat) seems useless and unhelpful. Most of the phone representatives seem friendly and helpful.Wake up, ASUS!
The laptop RMA service is performed within an adequate time frame (2 weeks, taking into account 6-8 days total for shipping to and from the service center), although the quality control of products leaving the service center seems subpar (did they really check that my laptop was fixed before sending it back to me?).
ASUS products still have a ways to go in terms of quality check prior to product shipment to match up to Apple standards. To be honest, as much as I like the Zenbook and PC’s, I’m not sure I would buy another $1000 laptop from ASUS again after this. It seems absurd that for a brand new laptop, I have to go through numerous phone calls and a month or more of back and forth before things are back to the way they should have been when I first purchased the laptop (let’s hope it stays that way).
[Edit: Please read the comments. This approach does not seem to work.]
[Edit: It seems that disconnecting and reconnecting the battery has had some success for various Zenbook users. Note that this will void the warranty (which is nothing other than absurd, but be warned).]
[Edit: Perhaps this is an easier trick than reconnecting the battery? Asus tech recommended one commentator "disconnect the power cord and press the power button for 30 seconds, for a battery reset" and then plug it in and let it fully charge.]