HELP: MBR Problem

[muddyfox470]

Ok ok

I was an idiot to do this, but I didn't check the cable and I managed to plug my volt modded cable (12v to 7v) into the adapter before my harddrives causing them to be under volted...


Now, I realise the problem think what an idiot I've been, remove the cable reboot, and the system won't start. It gave me an MBR 1 Error. So I try fixing the MBR via the Windows system disk (and fixmbr), no luck it now states:

non-system disk

So I am rather naffed off as to what I can do. Now can I just say, both harddrives are working perfectly, they spin up and they turn on etc, and each of the partitions are fully accessible (no corruption) via the Bart PE Builder disk I have to hand.

What is the best course of action? I haven't fixed boot yet as I want to ensure that the data on my other partitions on the harddrive is conserved before doing this. Otherwise I better back up the most important stuff. 2 Harddrives are affected (both sata 200gb) with 3 partitions on each drive.

What can I do to get both to work? Does anyone have any ideas or pointers so I can preserve my data and save myself a full system reinstall ?

Every tiny bit of detail is much appreciated

Thank you

Ian

PS. I'd love to get this back up and running asap

[muddyfox470]

Just to let people know I'm gonna read through this

However if people can give me any ore direct info that would be much appreciated

Cheers,

Ian

I have now tried fixboot and bootcfg (in progess)...

[Sema4]

ummmm, if it was working before, undervolted as it was... why not just put it back that way... Im a great believer in the old saying 'if it's not broke don't fix it'

How long has it been running successfully undervolt ?

If I were you, I would probably wire it back up the way I had it and test it to make sure all is running as it should be, and if it works, leave it alone...

[muddyfox470]

Sorry, I undervolted the drives, the system didn't boot up, removed the cable (then realised the cable was broke) then got the MBR Error 1 popping up on screen - so it wasn't working with that cable in place.

Just running through bootcfg to see what that brings up otherwise I'm at a loss as to what I can do :s

Cheers

Ian

CHKDSK found one or more errors on the volume:
5973768 kilobytes total disk space.
33601892 kilobytes are available.

[muddyfox470]

I still cannot get it to boot. Is there any chance I can get some fresh boot.ini, ntdetect.com and ntdlr files to test and see if they allow the system to boot?

What should I do next to try and get this PC up and running again Please please please help me.

Ian

[Sema4]

in order to provide a boot.ini file, I would need to know what partition your OS was installed to... you said each drive was partitioned in to 3...

Also, is it XP home ? or pro ? or media centre ?

Have you tried getting the system to boot with just one drive connected, instead of both of them ? No chance you have swapped the SATA cables around at the same time you mixed up the power cables, and it's trying to boot of the non-OS drive instead of the one with the OS on ?

Try each drive in turn, one at a time, if the first one fails to boot, try it with the other one. Check the BIOS and make sure the boot drive is correctly selected when you only have one drive connected.

I really can't see undervolting is going to damage anything, giving it 7v on the 12v rail, is a lot safer than giving it 12v on the 5v rail...

Im not even gunna ask why you have a modded '7v' power cable anyways...

[muddyfox470]

I've tried every combination, different cables, only the one drive connected etc etc, same error each time

I have done all the procedures in my previous posts regarding the recovery console and all the partitions are still available and accessible via Bart PE.

My system is XP PRO, on the root of the first master i.e. c: drive (default)

I cannot understand why the undervolt would have done this to the mbr etc :s but obviously its not healthy feeding it that. Reason for volt modding is for fans, i didnt subsequently use it for fans (due to a new install) I should really check the integrity of cables next time before connecting anything to it (it is because I had to accommodate my new gfx card, and i had left the pcie cable back home so needed to use a molex adapter etc).

Thanks for your suggestions; keep it coming

Ian

[peterb]

I can't be certain what the failure mode is by applying undervoltage. Worse case scenario is that the platters failed to start (or only ran slowly) but the heads still tried to load - however as the platters weren't up to speed, they scraped across the surface of the disk instead of flying above them. However the (embedded) disk controller should prevent the head from loading unless the platter is up to speed, so I'd have thought that is unlikely.

Best case scenario (and the most likley) is that you have just corrupted the mbr, so applying a fix should fix it. The fact that you can see the partition table is a good sign.

However if you want to be super safe, buy another hard drive, reload the OS onto it, then connect the suspect boot drives to see what is there. Copy the critical data off it, the apply fixmbr and see if it will then boot. If it does you can boot off that, reconnect the second suspect drive and check that the system is OK. If so you have probably done no harm, although it would be worth interrogating the SMART parameters to see what that says.

If it doesn't boot off the original disk, put the new one back and connect the second drive to see if that is OK.

One other option would be to boot the computer from a linux live CD (Knoppix, Ubuntu, Fedora etc) and have a look to see what data you can see that way which should give you a good idea if the disk is seriously damaged or not.

[muddyfox470]

One other option would be to boot the computer from a linux live CD (Knoppix, Ubuntu, Fedora etc) and have a look to see what data you can see that way which should give you a good idea if the disk is seriously damaged or not.

As I mentioned I have used Bart PE Builder which is commonly used for recovering data (basically a live cd windows as it uses a lot of windows files for it to load - you make the cd from the windows disk)

Anyway on that all the partitions are visible, accessible and data transferrable. But ideally I'd like to fix the harddrive to save me having to back up all the data and transferring across. I have a copy of my most important files etc. Just would rathre save the hassle of reinstalling everything.

Thanks again for your help

Ian

EDIT: here is something interesting, it states an mbr error 1 even without the drives connected at all. doesn't it normally state that no system disk has been detected in this case? regards ian

[peterb]

In that case, just boot from the windows CD to recovery mode and run the fixmbr tool.

[muddyfox470]

Hold yer horses

Ok, I was just changing over external harddrives so I could start to transfer files when I realised I hadn't tried the boot process with none of the sata drives connected, booted it and it came up with the mbr error 1 remark.

Thought to myself what a numpty, disconnected the usb drives (which it had obviously tried to default to once the sata ones had failed and voila)

Working XP with fully working harddrives

Cheers for your help and time guys

Ian

[Sema4]

Check the BIOS and make sure the boot drive is correctly selected when you only have one drive connected.

As I said about 6pm tonight.... DOH !!!

Just glad you got it up and running, thanks for letting us know, was scratching my head over that one...

[peterb]

Glad it worked out!

[muddyfox470]

As I said about 6pm tonight.... DOH !!!

Just glad you got it up and running, thanks for letting us know, was scratching my head over that one...

Cheers, I knew you had mentioned it, but I steamed past in my race to get things fixed , as I couldn't understand why the bios would change any settings (i.e. boot priority) normally it just says no system disk detected.

Will be running disk checking tools later on today to see what damage (if any) has been caused to the disks.

Thanks to the both of you

Ian

[scrandman]

Glad you got it to work out, but there is a valuable lesson here.

When modifying molex plugs for the purposes of supplying 7V or 5V to fans that would ordinarily run on 12V, it is much safer to do the wiring change on the fan's molex as opposed to the PSU one. If the fan has a "pass through" connector, you should perform the same wire swap on both of them (i.e. the molex supplying power to the fan and also the other one that would be used to power something else). That way you can safely power a second device from the pass through molex without fear of blowing it up.