Netbook freezes randomly

Acer = All Crap, Everything Returned.

PS. Steve, there's only one core in the 751h but there's two threads.

 

Yes, I have thought of that and googled around for stress tests. I ran one called 'Heavy Load". Ran it for about 12 hrs and it all went fine, no crashes.
I found Prime95 now and I get a rounding error that supposedly shows a hardware failure after a few minutes. Now I would need to get my head around this program and its testing procedure and I know documentation for the program is plentyful - but really, I so don't want to do that.

I will play along with Acer for the time being. I will get the Diag program today or tomorrow, most likely it will hang as well, I will then work with Acer to get it going (with Steve's instructions ), then it will run and probably show no fault. Then I will see what Acer support suggests next. At some stage the case will get passed on to Level 2 or Level 3 and that is when the rubber meets the road and people with in depth knowledge will be working on it.

At least that is how it normally works with tech companies. I think I just have to be patient and get past the initial Level 1 help desk procedures.

 

Hi. Yes I realise that there's only a single core, but XP sees it as two cores (the real one, and the virtual one). Prime95 then runs a thread on each of those, and from the couple of tests that I've done, it's the second one that fails. It might just be that it fails first, because one thing I noticed is that both "cores" don't seem to get stressed to 100% at the same time.

I'd found Heavy Load too, and agree that it didn't seem to have any problems. However, the only thing you are likely to get from that is either a BSoD (which isn't really a problem on the 751h, as far as I'm aware) or a freeze (which seems to be a random unpredicatable event).

However, Prime95 actually measures the results that the PC calculates and compares them against known results. Bascially, the two attempts I've tried have resulted in errors - this tells me there's something wrong with my machine. It shouldn't get any of those calculations wrong. Whether Acer will accept Prime95 as evidence, I don't know - I'll guess we'll find out later today.

I would urge everybody to run Prime95 overnight on their machines (I've had one failued at 4 hours, and one at 9 hours). It's very simple to run, even though it looks complicated; you don't want to join GIMPS, you are just stress testing. Simple selected "Torture Test" under the options menu, and accept the defaults. You should see one "main thread" and two "worker" windows". Just let it run. If it fails then it will be obvious in the Worker window, and the icon turns from green to red.

It would be useful if people who don't have the freeze, or have had their machines "fixed", run the test too. If we can show that they run Prime95 without a problem, and the freezing machines have failures, then it's a good way of testing for the problem.

I'll post again when I've spoken to Acer.

Cheers,

Steve.

 

I have run it four times now.
First run gave me an error after about 9 minutes
Second run after maybe 30 minutes
Third run (I ran it together with "Heavy Load") resulted in a freeze after about 2 hrs.

Then I put back a "clean" image of the OS (one that has never had a crash) via Acronis and ran it again. That fourth run, running all alone again, froze after 2:15.

My next step will be that I run it on my other 751 that so far has had no issues with the freezing problem.
I will also turn the one with the problems back to factory default and run Prime95 then - if it freezes again, that should be quite a good indication that its not a "software" issue (which I really don't think it is, it would be too much of a coincidence that so many people who experience the problem also have that "rogue" piece of software / driver running).

I will also give this "CPU Stability Test" a go: http://majorgeeks.com/CPU_Stability_Test_d215.html - wonder if that one will cause a freeze too?

 

That's really interesting - your's fails much quicker than mine, which is possibly why I've only seen the "freeze" the once. It will be interesting to see how well your machine that doesn't freeze does with the test.

I'll try running that stability test today. My 751h is being picked up for repair tomorrow, so hopefully they will find the fault and repair it.

Cheers,

Steve.

 

Does anybody know if exists any correlation between AO751h with or without 3G and Bluetooth modules, and freezing episodes?

I've noticed that since my netbook came back from assistance, freezing episodes decreased.


Hope it lasts forever!

 

tomoaca, so you had yours sent in for repair? What did they do during the repair?

As far as 3G and bluetooth are concerned, mine has no built in 3G. It does have bluetooth (which I have never set up as I am not using it).

 

They exchange the HDD and the 2 Gb RAM memory for similar ones. I would like to know if I could exchange my 2Gb 667 MHz RAM memory for 800 MHz and than obtain better performance. I'm thinking of put 3G and Bluetooth modules too. Is that possible, or I have to exchange motherboard?


Thanks!

 

I am afraid, changing the RAM to "faster" RAM will make absolutely no difference to the performance. It only means that the RAM CAN(!) be written to and read from faster - by a system that is capable of doing that. It is all working together and the bus speed is set and hence the speed at which the RAM is used it also set. Faster RAM would just sit there twiddling its thumbs knowing it could do much faster work - if only the info came in faster from the board. (Unless you want to go into overclocking - that is a different story.)

Bluetooth and 3G "modules" cannot be added without changing the motherboard unfortunately. Your best bet is to go via USB.

 

That wouldn't fix my problem because I had already installed 2Gb RAM, and a SSD drive and still had the freeze. I suppose it's possible that there are different causes for people's problems, but my gut feeling is that a lot of them are CPU based. Those people who have had repairs which involved new motherboards will have got a new CPU (even if it wasn't upgraded) as I believe that the Z520 is surface mounted, and so I doubt a repair workshop would go to the trouble of attempting to remove/replace the CPU.

Cheers,

Steve.

 

I agree Steve and I think we are on to something with the Prime95 program. I have now run quite a few tests on both my 751s and the results are very consistent.
- The one with the freeze problem ALWAYS shows up errors in prime95, and if I let it run long enough, ALWAYS on both "workers" (that is Prime95's terminology for the CPU threads I assume). The longest I had to wait was some 8 hrs, but it is usually way less.
- The one that does not have the freeze problem has not had a single error reported, even after a single run of 26hrs straight and another one of 18 hrs.

I swapped the memory module between the two - with the same result.

I must caution myself a bit here and concede that I have so far established a correlation of "calculation errors" occurring on one of my 751s and freezes - and lack thereof on the other unit, but that by no means establishes a causation. Nevertheless, its all sort of making sense. The other stress test programs I have been running (CPU StabilityTest and Heavy Load), did not cause any freezes (limited time runs though), but the problem may be subtle enough for a stress test to happily run over any floating point errors. Prime95 only once caused a freeze, the other times it just sat there with the report saying that a calculation error has occurred - job done, without causing a freeze. If there is a problem with the CPU(?) and it does now and then provide "wrong" results, then the symptoms we are all having with more or less random and more or less unrepeatable freezes do make a lot of sense.

BTW, if anybody is running prime95 and wondering where the results are, you need to look in the results.txt file in the directory where you started Prime95 from.

I am still waiting for the Acer supplied Diag program to arrive. I will give that ago and then report back to them with the results (Diag andPrime95) and see what steps Acer recommend then.

Reason for edit: Typos

 

Well, I have to say, you've made my day. That correlation between errors on your freezing 751, and no errors on the non-freezing, despite the small sample size, gives me comfort that we do indeed have an indicator to show whether the problem is fixed or not. It will be interesting to see what the repair centre say and do about my laptop now it's with them, but I think I'll ask the two other people I know with 751s to run Prime95 and see what the outcome is - one of them has definitely reported freezing.

I notice that Prime95 was mentioned earlier in this thread, but I'm a bit surprised that it wasn't given a bit more credance at the time.

Cheers,

Steve.

 

Well, so far I can't complain at the service...

- Monday report the fault, and request repair.
- Tuesday laptop collected.
- Wednesday eMailed to say they had received it.
- Thursday eMailed to say they had repaired it, and it was being sent back.

It didn't take long for them to repair it (assuming it is), so I'm guessing this is a problem they are aware of, and they have a standard fix for it. Will report back when I get the machine and have had a chance to run Prime95 on it for a while...

Cheers,

Steve.

 

I can't wait to see the result.

I have just logged my third ticket with Acer support requesting repair. I still have not received the Diag program from Acer, but that is pretty much irrelevant anyway. I used my version of the program, did exactly what you suggested with the program and got exactly the same result.

While logging the support ticket I exactly explained the process we went through with Diag and then the other stress test programs and also the results I get with my second, non-problematic 751. Lets see hat happens from here.

 

I just sent my netbook to texas for the 2nd time. At least Acer pays the postage both ways after I paid it the 1st time. I'm guessing they are not going to do anything.

Has anybody figured out a way of reproducing the freeze consistently while browsing the internet?

 

mine used to freeze horribly.. and ever since i upgraded it to windows 7 i havent seen any freezes, except once when the laptop got really hot during a skype call with audio and video call..which lasted 3 hours. when it used to only last a few minutes when it was on it's stock OS.. maybe it's the way the operating system addresses the components of the laptop?
just an idea.

 

I have not been able to get it to freeze "reliably" (I can't believe I am writing this :? ) It really is a random thing that in my case generally happens when scrolling in Chrome or MS Word (that's about the only apps I run consistently). I used to get a regular freeze in Skype, but that is no longer the case. I suspect (only suspect) that this has to do with the driver. Have a look in one of my previous posts a page or so ago, I give more details. There is also a separate thread if you anybody is interested.

That is very interesting I must say.
I hate to do this to you, but do you mind running Prime95, a sort of stress test program? You can download it from here and Steve gives great instructions on how it works and how its run here.
I don't know how much you have read of the past pages this thread, but at the moment Steve and I think there is a correlation between machines that have the freezing problem and showing "calculation errors" in Prime95. So far we only have a small sample size, but if you could run yours for as long as possible (many hours, not minutes ) and let us know, we have one more data point.

You too, freezer?

Edit: corrected download URL

 

The Boys From Brazil - if you are still looking for answers, you aren't going to find any here. It's the way of the world. You buy off a man who knows a man, and the minute you have a problem...well nobody knows the man !

There is no quick fix. It needs repairing.

The rest of you...........well, I just don't know what to say. You are perpetuating the belief that there is a quick fix and you are going to extraordinary lengths to
find something that simply doesn't exist. Stop kidding yourselves that you can find the answer. If there was a quick fix even Acer would put it out there!

82 pages ! 82 pages of the same bloody drivel.

Of course Acer know that there is a problem. I usually laugh at conspiracy theories, but it wouldn't suprise me if some of these responses aren't actually
actioned by Acer themselves just to keep you going. Fix it with a repair. I came back and expected this site to have run it's course, instead it has taken on a new
face......Dr. Diagnosis.

Diagnosis is not the cure ! Repair, repair, repair.

Send it back, it is actually painless once you let it go.

And the repair or the repair agent is usually pretty fast (inside a week).

And much as I can safely say I won't be buying Acer again, this baby is a dream to use (after I sent it back for repair).

I will reiterate. Get it repaired !

 

I just checked FEDEX and Acer just received my netbook today. The funny thing is when they turn on the netbook. I set it up so when they turn it on, it will automatically open the internet browser and go directly to this forum.

Hi Acer Technician,
I hope you take this forum seriously. Especially since you own it. Please repair my netbook and not just reinstall the OS.

 

Bob, very much appreciated, its always good to read some well meaning and well informed posts. I wonder if you did in fact mange to read any of the Dr. Diagnostis post that you seem to like to much. If you did, you somehow must have missed that most of the diagnosis Doctors already have sent their machines in for repair - at least once. Mine however came back from repair with the same problem still there. So, now what do you suggest is the right thing to do in order to solve the problem (but make sure we don't prolong the drivel?)