Download corruption and CRC errors.
 

Hi guys, this thread has seen quite a few forums in the last two weeks as I attempt to diagnose a problem that's been plaguing me. I've been a Virgin Media customer for over 8 years (Since they were called NTL) and had no issues but all of a sudden last week all my downloaded files, Rar files and Executables so far both reporting corruption at a rate of around 70%.

For example I use a program called JDownloader to download things from Rapidshare, the program will report 'Connection Lost' and then occasionally 'CRC Error MD5'.

So at first I of course assumed this was an issue with the program, I reinstalled and updated etc, still there. Then I tried downloading some of the corrupt files straight through Firefox to take JDownloader out of the equation.

I still got corrupt files however and the problem was also now affecting Exe files, perfectly legit files that should have worked.

https://www.cableforum.co.uk/images/...2010/02/92.jpg

So at this point I turned to the hardware, maybe dodgy RAM or bad sectors on the HDD, I'd looked around on lots of forums and seen this suggested many times. I ran HDD checks and overnight RAM checks, all came back OK. So I used a laptop connected to the network to download the same links from. They all came back ok, but the second time I did it they too had corruption of ~50% of the files.

So it can't be the hardware. I format my computer, reinstalling Windows 7 on to a different harddrive.

Still nothing.

So it must be the network right? The router or the cable from the modem? That's what I thought, I replaced the router with a network switch just to see if that changed anything, the problem remained. So last ditch attempt. I plugged the modem directly in to the PC using a brand new cable (no small feat with it being around 20m long).

Still getting corruption errors.

It really can't be anything on my end, can it? A phone call to Virgin Media was very unhelpful with the usual 'turn it off and on again attitude' and the speed tests (Annoying as I never mentioned speed). I was told to turn off the firewall on my router, even though I told him I had replicated the problem without the router even being connected. Seems I have absolutely no hope of solving this from VM 'tech support.'They told me the line had only disconnected once in the last month and it was a stable connection. Could it be the modem then?

So here I am, a broken man. Does anyone out there have any idea what I can do to fix this?

Specs:
HDD 1 - Samsung SpinPoint F1 HD103UJ 1TB Hard Drive SATAII
HDD 2 - Western Digital WD5000AAKS 500GB SATAII
RAM - Corsair 4GB (4x1GB) DDR2 800MHz/PC2-6400 XMS2
GFX - Powercolor ATI Radeon HD5850 1024MB GDDR5
MOBO - Asus COMMANDO P965 Socket 775
CPU - Intel Core 2 Quad Q6600 B3 (2.4GHz 1066MHz) Socket 775 L2 @ 3.0ghz
PSU - Seasonic M12 700W Modular PSU
OS - Windows 7 Premium Home 64bit

Update:

The problem seems to start with connection freezing. The download speed and estimated time parts just stop (At this time all the lights on the modem also freeze) then it reports this 'Connection lost' thing. Seems to happen every few minutes.

https://www.cableforum.co.uk/images/...2010/02/93.jpg

Re: Download corruption and CRC errors.
 

Have you recently updated/changed your firewall/AV settigns/programs??

Re: Download corruption and CRC errors.
 

That's the thing mate, this happened and I did think about that, I've changed nothing at all. But since then I've changed everything and it's not fixed it.

If it was something on my computer then the error would not have been replicated on my laptop. I have tried resetting the router, returning to factory defaults, updating firmware. Formatting my PC. Had the connection plugged directly in to the PC ruling out a router problem. This is why I'm so stumped.

Re: Download corruption and CRC errors.
 

It could be hardware related (i.e..the connection) but more likely to be software... Do you have another PC you can test it on connected directly to the modem, this will confirm whether it's VM.. If not then add the router, then retest, then add your download manager and retest, then the firewall, then the AV...you get my drift ;)

It's exactly how you modular check suspected hardware faults/conflicts, you drop down to the very basic needed to work then you add the bits from there testing after each addition

Re: Download corruption and CRC errors.
 

The other possibilty is that the files are corrupt before you downloaded them.

Re: Download corruption and CRC errors.
 

I have a MacBook Pro which has Windows 7 running on it, I shall give that a run on OSX and download a lot of files see if there's any corruption with them, then we can rule out Windows if it still happens and focus on it if it does. Thanks!

Hom3R: Not at this rate, I've been downloading a lot from various places for years and never had a single CRC error, now in the past week I have it affecting 50% of all downloads. Nah definitely something wrong IMO.

To the tests!

Re: Download corruption and CRC errors.
 

I tried a downloading program called Orbit and like you I end up with a lot of files with CRC errors, (I also use VM) I have never tired Jdownloader and don't want to. I use a mini downloader which is part of IE7Pro, an add on for IE free (Google it) and although nothing as sophisticated as other downloader, it is fast and I have not had one file with CRC errors.

Re: Download corruption and CRC errors.
 

This thread isn't about illegal downloading but instead about CRC errors when downloading, if you can help please do so, if not then please don't go off-topic

Re: Download corruption and CRC errors.
 

Well it's not me who'll get in trouble if a content owner comes by and finds CF facilitating file sharing - Google the string TMHSAG. Hit 'I feel lucky' if you want, it's that easy.

Re: Download corruption and CRC errors.
 

Yes I know exactly what TMHSAG is, but this thread is not about that, you have no proof as to if the picture he posted is even off his PC..

:rolleyes:

Now back on topic please

Re: Download corruption and CRC errors.
 

That was a test since it's got lots of links meaning it's a good way to test the problem. It's hard to replicate it without a list of links. What I normally download is not the point either, you don't know me.

Ok, removed it, sorry for any trouble caused, but please try and help rather than flame.

Re: Download corruption and CRC errors.
 

Excellent - I have removed my post and am seeking Hormone Replacement Therapy :D

Now then.

You use a router? Any software firewall, Zone Alarm, etc?

Usually CRCs are sourced from things like application layer firewalls on routers or on your PC helpfully trying to screen traffic to make sure it's ok and in between breaking it.

Try booting in safe mode with networking from behind the router. We know it isn't the router as you've already tried directly connected with no change.

To eliminate network corruption pop open a command prompt and do this:

ping -t -l 1460 www.virginmedia.co.uk

Leave it running for ages, and when you get bored hit CTRL-C and see if any errored.

You can also do the Mac equivalent if you wish too.

ping -fs 1460 www.virginmedia.co.uk

Don't leave the Mac one going for too long as it is a flood ping and looks like a denial of service :D

Re: Download corruption and CRC errors.
 

I use jDownloader to download from Rapidshare every day without any issues - have you tried changing which RS servers you use by default in your RS account ?

Re: Download corruption and CRC errors.
 

Thanks tried that matey.

https://www.cableforum.co.uk/images/...2010/02/90.jpg

Thar she blows. What next? :S

Re: Download corruption and CRC errors.
 

Not network related in that case - you'd have seen some errors if that were the case.

Next on the list would appear to be a nice long download from somewhere else such as the VM FTP site.

I despise Rapidshare in any and all guises so am quite happy if VM are messing with traffic to and from there but they aren't in this case.