Home

If while trying to read a disk with the View function CnW Recovery software no sector can read, or the sector is just displayed as 5A 5A 5A, it is possible that the media is totally dead.  Before giving up, there are several things that can be tried, sometimes media dependant.

The first stage with all types of media is to ensure that the basic reading / interface hardware is working.  Thus if trying to read a DVD, test the drive with a known good DVD.  If reading a memory chip, try a known working memory chip in the same card reader.

Range of error

It is important to know if the whole media has failed, or just part of it. This can be tested by using the Views sector function, and trying different values, within the range of the disk.  Most disks should start reading at location 0 (though some CDs start at 500, and mini DVDs at about 12,000).

The top sector on a disk is dependant on the size of the media.  For hard drives, and memory chips, the cacpcity is normally known, and as rough guide, the top location in MBs is twice the capacity in GBs.  For example, a 30 GB disk has about 60 million sectors.  A 512MB (0.5GB) memory chip has about 1 million sectors.  A sector is 512 bytes.

For CDs and DVDs, a sector size os 2048 bytes (2K).  The number of sectors on a CD / DVD does depend on how much has been written but a full CD could have about 350,000 sectors and a full DVD could have just over 2 million sectors.  As mentioned above, CDs and DVDs do not always start at sector 0.  Sector 16 is normally vey important, and so should always be tested

If every sector attempted fails (ie error message or 5A 5A on the screen) then there is not much hope with the present hardware.

Hardware variations

For a CD /DVD it is important to make sure that the drive is a RW drive, and compatible with format being used. Often though, reading marginal CDs can be drive dependant.  Thus try the media on a different drive, there may be some luck.

For a hard drive, the prefered way to read the drive is in a USB caddy.  Try a different caddy, or possible connect the drive directly to an IDE connector in the computer

For a USB memory stick check that the connector has not been broken. Very occassionally it is possible to repair these, but does require a significant element of good luck.

Partial reading

If some sectors can be read, then the next stage must be to make a disk image.  Using the Image function an image can be created. If the start of the media cannot be read, it can be skipped.  The image will be padded (with 5A 5A).  It is also possible to skip a section. If the copy goes very slow due to failed sectors, the copy can be cancelled and started at a higher location.  Any missing area will be padded.

Once an image has been created, a recovery can be attempted, and it is possible that much data can be recovered