Solved BSOD every 15 mins - multiple stop errors

[Seanobr]

Hi,
I'm trying to help troubleshoot my gf's laptop. This is my first BSOD experience so sorry if I do this wrong!

General Info:

As I've said in the thread title, the laptop has been blue screening every 10-15 mins since 25-08-2012.

I've seen three stop errors so far. They are: PFN List Corrupt 0x4E, Memory management 0x1A, and cache manager 0x34

When we bought it from Harvey Norman 6 months ago, it had additional modules installed (or replaced) to 12GB RAM... *cue horrified music*. I'm suspicious, except that it has been fine this entire time.

Earlier in the computers life, I've had to flash the BIOS with an update (because the tool to adjust screen brightness was not functioning), then was prompted to do it again some weeks later by Toshiba Bulletin board, only to find it had flashed it with the same version. No problems occurred.

Other than those two things, I can't say anything dramatic has happened to this PC. Used an external monitor that Saturday that BSOD first appeared, but blue screening is happening with no monitor attached now also.

I have tried:
System Restore to a point before the monitor driver was installed that fateful day. It BSOD'd during the system restore...*hits head against wall*...

I have run windows memory diag tool. It only said that errors were detected.. thanks...

I also ran memetest+ at boot, but didn't really know what I was doing or what any of it meant. But I do remember some red errors being detected.

I have checked that the memory modules are seated properly.

I have run AVG virus scan (blue screened during). Booted in safe mode, ran AVG scan from command prompt. Found no problems.

Sorry if that's too much/useless info. Attached is the ZIP file. Thanks for any and all help!

EDIT:
I also wanted to add - I have noticed a white flashing line (like a video error) on the desktop every now and again since the BSOD issue. Some kind of video ram error perhaps?
And the WORST THING - it now thinks windows isn't genuine, and I can't check for Windows Updates.

Also, I didn't mention any system specs...
Windows 7 Home Premium 64-bit
AMD A6-3400M 1.4GHz
12GB RAM

 

[Dwarf]

Hi Seanobr and welcome to W7 Forums

What is the full model number of the Toshiba laptop in question? 12GB of memory for a laptop seems a large amount, with 4GB typically being the maximum memory supported by many laptops.

 

[Seanobr]

Thanks Dwarf for the speedy reply.
Laptop model is: Toshiba Satellite L750D
Yes 12GB RAM is such an overkill.. but it was a free upgrade as they were trying to get rid of these models.
I watched the store man install the extra RAM on the counter in the store...

 

[Dwarf]

I would say that it is a memory issue, especially where Toshiba themselves say that it only supports a maximum of 8GB. Click the following link for more information (click on Detailed Specs and then scroll down to Memory): Model Content Page

 

[Seanobr]

Indeed. Infact the exact model can be found here:
PSK36A-034008 - Toshiba Satellite L750D Computer - Australia :: Toshiba :: Computers, Laptops/Notebooks, Tablets, Televisions, DVD and Blu-Ray Players, Camcorders, Storage, Accessories, and more
I think Australian product codes are a bit different. Non-the-less, it's still expandable only to 8GB.

Could you confirm that my next step should be remove the additional memory module and test?

 

[Dwarf]

Yes. In fact, test each module separately in each slot.

 

[Seanobr]

The latest addition to the problem is a back up to my external hard drive fails 100% of the time before it even begins. As soon as I kick it off it says Error no files were backed up. I view the .txt file of files not backed up and it says C: is corrupt.

Going to run Check Disk utility now.

 

[Seanobr]

Check Disk came up clean.

Turns out that there is an 8GB +4GB RAM modules installed in this laptop.

It doesn't boot with only the sole 8GB module in Slot A (as the manual states, if using one stick use Slot A). It just continually runs Windows start up repair and reboots, over and over.

Haven't tried the 4GB stick on its own. I just put both modules back in so I could boot properly.

I managed to get system restore to work (finally without blue screening during the process) to the point before BSOD started happening. Ran it for a couple of hours fine. Installed Windows updates, and behold.. BSOD started again.

I think I have narrowed it down to either KB2729094 or KB2732500.

I did system restore again, and then hid these updates from being installed. I had to run WGA again as it was telling me windows was not registered. This worked no problem.

Now am leaving the computer on for x amount of time (at least a couple of days) to see if anything unusual happens again.

Beware of nasty Microsoft updates!!!

 

[Seanobr]

Okay, it's not those updates.
Checked my laptop this morning and it was at a black screen with one line of text saying something about headers crashed check sum didn't match equal sum or something.

I have not tried the initial suggestion of trying each module in each slot. So far I know the following doesn't work:

SlotA: 8GB
SlotB: Empty
Wouldn't boot

SlotA: Empty
SlotB: 8GB
Wouldn't boot

SlotA:8GB
SlotB: 4GB
Unstable (BSOD)

Will be interesting to see if the system is stable with only the 4GB module installed.

Will post again tonight.

 

[Seanobr]

The problem is almost definitely with the 8GB RAM module.

Ran it all day with the 4GB stick and it was stable. Ran Windows MD tool and it found no errors. Can anyone suggest any other tests I should try?

So now that I am fairly sure where the problem is.. the question I have is why did it fail all of a sudden? And how can I explain that to the store I bought the laptop from? I hardly think they will accept me waltzing in with a loose 8GB stick of ram and saying 'here's the problem'...

 

[cassline]

So I recently had the EXACT same thing happen to me. I found out it was a faulty 4gb ram stick that I added in 3 months ago. I kept the original in now and it works fine. Does your computer act the same when adding a new one in? If you figured out how or why this happened let me know. I am very curious myself as it took me 3 days to pinpoint the exact issue. I also had to re install windows because while restoring it, it failed. It was a nightmare as it wouldn't let me install windows and blue screened on me when I tried.

Apparently ram can go bad at anytime. That is all I have.