3TB FAT32 Bad Jump & Sectors

How to use TestDisk to recover lost partition
Forum rules
When asking for technical support:
- Search for posts on the same topic before posting a new question.
- Give clear, specific information in the title of your post.
- Include as many details as you can, MOST POSTS WILL GET ONLY ONE OR TWO ANSWERS.
- Post a follow up with a "Thank you" or "This worked!"
- When you learn something, use that knowledge to HELP ANOTHER USER LATER.
Before posting, please read https://www.cgsecurity.org/testdisk.pdf
Posts: 1
Joined: 01 Feb 2015, 22:48

3TB FAT32 Bad Jump & Sectors

#1 Post by safailla »

Hello! First off I would like to say thank you to everyone involved in the creation of TestDisk and all who continue with its support. I am continually amazed by the depth and power of this app, its truly awe-inspiring.

With that said I would like to apologize in advance, this is my first post here and am not sure if its even in the right section for what I am searching for.

My problem is this, any and all suggestions are welcome:

I own a 3TB FAT32 External HD made by Western Digital. I have only one partition on it, and 2794 GB used up. I recently had a powersurge that browned out my PCB board. I obtained a new PCB and had the 8pin Replaced.
Upon reconnecting I noticed a failure to Mount and access, so I opened Disk Management (in both MAC and Windows) which then prompted me to reformat (Which I did not). I then started up TestDisk and went through the motions and begun quick searching. It is now 3 days later. I am Stuck on 68% and the dive is making a weird noise, not a clicking, but a searching sound, which it did not do up until this point. here is a photo of the situation.

Just kidding, the photo is 5mb and wont load in the attachments section, I type everything out below:

Disk /dev/sdc - 3000 GB / 2794 GiB - CHS 364801 255 63
Analyse Cylinder 249510/364800= 68%
Read error at 233383/251/49 (Lba=3749313756)

Unknown 84556894 33776997289835613 33776997205278720
check_FAT: Bad jump in FAT partition
check_FAT: Bad jump in FAT partition
Unknown 1154021070 2724724051 1570702982
check_FAT: Bad jump in FAT partition
MS Data 2503320889 2509499658 6178769 [M-*_C~^M-v^L ^A^YM
check_FAT: Bad number of sectors per cluster
Unknown 3201272790 6137995603 2936722814
Unknown 3281315769 169985505208 166704189440 [ #~PM-vF]


I am a bit cautious on hitting the Stop with out more knowledge but it has been another day now and its still stuck on 68% and the Cylinder number hasn't moved at all. Can anyone help me or advise me on this situation, I really don't want to completely loose 3TBs of data :[

Thank you In advance, Allen

User avatar
Site Admin
Posts: 5432
Joined: 18 Feb 2012, 15:08
Location: Le Perreux Sur Marne, France

Re: 3TB FAT32 Bad Jump & Sectors

#2 Post by cgrenier »

The read errors shows that there are bad sectors. You need to clone the disk to a new empty 3GB or + disk using gnu ddrescue: http://www.cgsecurity.org/wiki/Damaged_Hard_Disk