I have a WD400BB with several bad sectors (not only UNC but also IDNF, etc.) and a lot of weak sectors. I have used scan from MHDD with erase delays and remap but it doesn't help. DLGDIAG low level format hangs as normal format from Windows does.
It looks like sectors system area (not only data area) is also damaged. What is better to do in this case, use assign or specialized tool from PC3000?

It does not sound like you need the data from this disk as you tried to Low level format it, so why do you need it repaired?

If there was any serious system area damage I dont think DLGDIAG or Windows would have access to it. Sounds to me like a failing hard drive. Is there a pattern in MHDD? Maybe there is one head failed or dirty.

In my opinion when bad sectors appear, no matter how often the bad blocks are remapped, its time to save the data and replace the drive

Replacing it would be a lot easier.

i think there is a problem with your firmware data if u have pc3000 chk the fw structure repair any modules if they are bad and then internal format it .

Thanks hddguy and rameez for your advice.

I do not need the data from the disk; i love hard disks (especially WD) and i am just trying to know everything i can. I also hate broken things. Bad sectors is a usual hdd problem and perhaps we could discuss general recovery strategies.

Now, i do not think it is a failing (or dirty) head, because the bad sectors appear only in the last third of the disk. I also have another disk (WD 10G) that gives a pattern of weak (and bad) sectors when scanned with MHDD from the beggining to the end; that definetely looks like a head problem.

Also, i do not think it is a firmware problem, because as hddguy said , the disk could not be accessed from Windows in that case.

The disk when first scanned with MHDD had about 1000 UNC blocks and only 1 IDNF. After a few low level formats with DLGDIAG and scans with MHDD, the disk now has fewer UNC blocks but much more IDNF and AMNF blocks (<100). Could it be somehow damaged by DLGDIAG, or a failing drive just became worse through normal wear?

Could the problem be a scratch on a platter? Would it be visible if i opened the disk? (i already know that doing so would make further repair attempts almost impossible).

IDNF and AMNF bad sectors could not be hidden by assign command, would it be possible to use PC3000's WD specialized tool for recovery? Any help on that matter would be greatly appreciated.

I made some research about fixing hard disk bad sectors and I found something at <moderator: removed spam site> Good luck.

Sometimes in hard drives many bad sectors apear because of partial firmware damage in WD not most of the times but when IDNF appears it has got to be 90% firmware data damage . and if u have low level formatted the hdd then the bad sectors should go away . Can u post the SMART i can help u better .