Files get randomly CORRUPTED! Hash mismatch, but they *mostly* work. Advanced tests

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Dan_Aykroyd

New Member
Hi!

I just found this forum and registered to join this community and further participate in it! Seems pretty big... ;)

Anyway, I have quite a problem in my PC that is *literally* taking sleep time from me. The thing is that files randomly get corrupted! Let me explain...

Some time ago (a month aprox.) I detected that the Linux ISOs I downloaded from BitTorrent (using latest uTorrent client) downloaded corrupted. I.E.; the file would complete OK, and then, let's say it was a RARed file, when unpacking it would give a 'CRC error' on it. After some days, I tried going back to uTorrent and 'forcing a recheck'; then it would rehash the file, and the 100% file from before would be completed to 99.7% (for example) now. Redownload; file unpacked OK.

That was the first stage. All these images I downloaded I had to do the same for them. No big deal (for now), until I reformat again and I thought it would fix by a fresh installation of Windows.

Now, the real problem here began when I copied an Acronis True Image .TIB file from my laptop to my desktop, via ethernet cable. I copied it, burned it on a DVD (in my desktop), and then found that ImgBurn would fail the Verify stage. I said..: 'well... it SHOULD still work.'. Then, I went to Verify the image (file) with built-in Acronis verify function. Guess what? It failed that verification too! The files was corrupted! First gross check I did, the file has the same bytes size in the laptop, desktop and DVD. (At that stage, I didn't know what I was going into...!)

The fact was that in the laptop, the file would verify OK with Acronis (it was OK there). So, I tried recopying it (again, over the ethernet cable) to my desktop. Burned. Corrupted again. Neither ImgBurn or Acronis would verify OK the disc image / file . Right there I started to worry...

I went and burn an image of a DVD video disc I had from quite some time ago, and ImgBurn would fail the verification too! The funny thing here, is that the movie still fully played; and also the Acronis Image would mount as a virtual unit, from which I could extract files from, and those files would work OK too! For example, EXEs from installations programs, would install the apps OK! How can that be!? Maybe "a Bit" was corrupted, and thus fail verification but mostly "work OK"? Shouldn't they be totally useless files?

At that point I still thought, "well, maybe a virus / windows service / whatever is messing here, will reformat and fix". Well, that wasn't so.

I reformated, installed a fresh Windows, antivirus (NOD, Kaspersky, Antivir, Prevx), full scanned with them. Spybot full scanned to. Hard disks "chkdsk" with all the parameters to fix bad sectors, unmount, etc. Still tried to copy the original (UNcorrupted) TIB image file from the laptop, and even from the CD, and it wouldn't still pass the validation!

So, I started to think about "bigger" corruption here. I went and downloaded "HashMyFiles", a great free app to hash files! Runned it in the laptop, and in the desktop and... THEY WERE DIFFERENT! The hashes didn't match! So THAT was it I said! Now, I tried with smalles files (200 MB), and they were the same hash in both locations! Tried with 600 MB and the hashes were different!

Again, and to further find what could be going wrong here, I booted from outside Windows, with Acronis True Image boot disc (which runs the same app that in Windows, but boots from a standalone CD), verified the image file over the very same DVD that restores and verifies OK in the laptop, AND IT STILL WOULD FAIL! OMG IT WOULD FAIL EVEN WHEN BOOTED FROM A DVD OUTSIDE WINDOWS, WITH THE TOTALLY SURE 100% UNCORRUPTED FILE! WTF???

That's where I lost it. Now it isn't a Windows problem anymore. Even tried switching IDE channels and all the process would still fail. So it's not the cable neither.

What most troubles me now is... every app works perfect, Windows works perfect, drivers, internet, everything. And the computer corrupts files "as it wishes" and nothing crashes? How come everything still works? I really don't see where is the seed of the problem here. The motherboard if broken? Then again, if something so sensitive as a corruption to a file happens all over 3 HDs, how come everything still works flawlessly?

As you can see, I'm quite desperate and don't know where to turn or what to try at the moment. Please help me find a way to fix this. Any question, suggestion, whatever is more than appreciated! BTW, I'm running it in MS Windows XP SP2

Thanks in advance guys.
 
Most common symptoms of faulty random access memory are the following:

The system locks up
Error message about illegal operations often display
General protection faults occur during normal operation

You ever tried running Memtest86? It is a utility to test installed RAM.
 
Agreed. The burning process (and possibly file transfer/placement) mounts all relative data unto the RAM before proceeding. Faulty RAM would explain the intermittent/selective problems you are experiencing.
 
Hi guys, thanks for your replies :)

Yes, I've tried running Memtest and Prime95 (and it's multiple tests) to stress-test the PC and left them each overnight; both worked OK with no errors / hanging / whatsoever.

Also, the thing is that the PHYSICAL hash of the file in the HD is different! It's not that a "crash" occurs in 'real time' or a corruption of the memory; the file gets a different hash when I copy it or read it from, let's say, the burnt DVD...:eek:
 
Nope... I bought a brand new Lite-On DVDRW just for this and it's still the same...

Besides this happens also sometimes when big files are copied from one drive to another (inside the same computer, same IDE channel and also different IDE channel)
 
What a headache! I would just buy a new motherboard that can use your current RAM and save yourself the pain of continually troubleshooting if I were you.
 
I hope that I don't have to do that! That's the worse thing for me, it would be a mess; I've to find a new motherboard that fits the CPU chasis, all the dirt from all the time it's been there; a zillion cables hooked up at the back, etc!

Besides, if it was the motherboard, how could it be possible that everything works "so fine" besides some files? It doesn't "know" what to corrupt... I mean, the mobo doesn't "think": "oh, he is using nero to copy a big file, I'm going to change this '1' for a '0' so he gets a different hash"... I mean... if it wasn't working well, everything should crash! I installed WXP 5 times without problem, watch DVD ripped movies from the HD OK, copy files over to a network drive OK now (files that are 5 GB size)... you see... I really don't know what could be the problem!!!

I hate this f*cking randomness that doesn't let me follow a logical testing procedure anymore...

EDIT: Wow... another thing I detected is this scenario:

Original file in PC has hash: AAA
File copied to other device for the FIRST time has has: BBB
File copied to other device for the SECOND time has has: BBB
...
File copied to other device for the Nth time has has: BBB

So... you see, not only they get corrupted, BUT they get corrupted every time to produce the very same "corrupted" hash; not a different signature every time! For F*CK SAKE!
 
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I don't mean to be rude, I know your frustrated but there is no need type profanity. Please be a little more professional.

Have you tried any different versions of the DVD burn software you are using? Perhaps the bug is in the program you are trying to use.
 
What HDD are you using? Seems that the ECC on the HDD is not doing it's job. If your using one of those early perpendicular recording hdd, it figures. Before doing somthin else try defragmenting.
 
Sorry for the profanity, I am really astonished from the symptoms it produces...

The HDDs are three Samsung 80 GB IDE; corruption happens in either one of them, copying from/to the same drive and any combination. Besides, it also happens when copying to network, USB pen drive, etc.

About the defragging, I've tried a zillion times now to remove all partitions, recreate only one, all of them, unplug some drives and leave only 1 in (in either 1 of the 2 IDE channels), low level format, etc. And above all, when I boot from an Acronis True Image bootable CD and go to verify a image that resides also in the CD (and works / verifies OK in other computers), here I get a "corrupted image" message. How do you explain that??? No HD is involved in the operation.
 
:) this may sound easy, but try replacing the ATA100 cable. If, same, all symptoms lead to the main board's northbrige chipset. Can't think of anything else but trying with another mobo.
 
Yes... I've tried with several other IDE cables; with the same result!

Could it be the northbridge? What I fail to understand is how it selectively corrupts some files... I mean, if the motherboard was the problem, everything would be a mess! Windows would (if at all) boot and then at the next minute crash, BSOD, reset, whatever! But no! Here I can rip DVDs, watch them, install every kind of application, and also run Prime95 overnight and then run BurnInTest indefinitely some more, without a hitch!

Do you see what I mean?... :(
 
i see what you mean, i never encounter such a problem. i have no ideea besides replacing the mainboard.
 
HI again.

An update... I changed the mobo to a Soyo 6VBA133. The memtest program was giving random errors (sometimes completed OK, sometimes with errors), and so I changed the mobo plus I bought all new memory modules. Here's the thing: it's still the same. Errors come in memory with Memtest86.

Prior to changing the motherboard I left running Prime95 for 24 hours without a hitch, so I'm assuming that the processor is OK too.

Oh, and I also bought a brand new ATX power source.

Men... I just have no words for this.

Please help, thanks
 
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