MENU
- Home

- File Repair

- Quickbooks Data Recovery

- Quickbooks Enterprise to Pro

- Exchange Repair

- File Conversion

- File Formats
- Products
- Services

- Newsletter

- F.A.Q.'s

- Contact Us

 
 

AutoCad Recovery

AutoCad Recover damaged drawing files

Applies to:
AutoCAD® 2005
AutoCAD® 2004
AutoCAD® 2002
AutoCAD® 2000i
AutoCAD® 2000
AutoCAD® Release 14
AutoCAD LT® 2005
AutoCAD LT® 2004
AutoCAD LT® 2002
AutoCAD LT® 2000i
AutoCAD LT® 2000
AutoCAD LT® 98
AutoCAD LT® 97

Issue

Drawing files can become corrupted for many reasons. The most common cause for corruption is when a drawing file is copied onto a floppy drive or a hard drive that contains damaged sectors. In this situation, some or all of the file(s) copied onto the damaged sectors become unreadable. Other sources of file corruption include defective computer RAM, power surges, usage errors, and network file transmission problems. Another cause for file corruption, although infrequent, is when AutoCAD® shuts down unexpectedly while the drawing is opened. Also, drawings originating from other software packages that have been translated into DXF? or DWG format can suffer through the file translation.

The most effective way to guard against this type of data loss is to make frequent backup files of your drawings. Although this document explains different ways of recovering corrupted drawings, file recovery is not always completely successful.

Even when a drawing can be recovered, some part of the file is often corrupted beyond recovery, therefore you must identify the part(s) of the file that were not recovered and consequently recreate the data. Instead, it is obviously better to use a "good" backup of a drawing so that you know exactly what data is contained in the drawing based on when the last backup was made.

Solution

Note that most of the recovery methods explained in this document can be used in all releases of AutoCAD® and AutoCAD LT® software.

Before Recovering a Drawing

Autodesk Product Support strongly recommends that you perform the following steps before recovering a corrupted drawing:

  • Make a copy or copies of  your drawing on reliable storage media. For example, if you suspect that your hard disk contains bad sectors, copy your files to another hard disk, a network drive, a floppy disk, or a tape. It is best to perform recovery operations on a copy of the file, since there are several different methods of recovery, and each method alters the file in a different way. For each recovery method, it is best to use a copy of the original file since recovery processes may alter a damaged drawing yet still not recover it enough that AutoCAD can open it. If you retain a copy of the original damaged file, you can then use another recovery process on the original file.
  • Identify and make backup copies of BAK files associated with the damaged drawing. If you open and save a damaged file without fully recovering it, you may overwrite a good BAK file with a corrupted BAK file.
  • Note that there is a mechanism in AutoCAD that prevents a good BAK file from being over-written by a corrupted BAK file. When AutoCAD saves a drawing, it also checks the file for corruption. If the file is corrupted, AutoCAD does not overwrite the existing BAK file. Instead, it creates backup files that have the file extension(s) .bk1, .bk2, .bk3, etc. Be aware that this process is not always successful; therefore, it is a good idea to make archive copies of good BAK files if you suspect that you have a corrupted file.
  • Try to identify the source of the corruption. For example, if you suspect that drawings are becoming corrupted by copying files onto a hard disk with bad sectors, you should identify and correct the problem with the hard disk before you begin to recover your files. By doing some investigation, you may find that there is more than one source that is causing the corruption or that your original assumption about what is causing the problem is incorrect.
  • Record any error messages generated by AutoCAD or the operating system. Note when the messages occur in order to find a connection between the messages and when the drawing becomes corrupted. Continue to record any errors or messages that are generated during the recovery process.

AutoCAD RECOVER Command

To use the RECOVER command on a damaged drawing, launch AutoCAD and open a new drawing with no prototype. Use the OPEN command to open the drawing. If AutoCAD detects that it is corrupted, a message is displayed indicating the file is damaged. AutoCAD then prompts you to use the RECOVER command to open the drawing, and a message is displayed asking you to enter YES to proceed. If you proceed, AutoCAD then scans through the drawing database to detect and fix errors. If the RECOVER process repairs the file so that it can be opened, AutoCAD then opens the drawing and a message similar to the following message is displayed on the command line:

    Command: RECOVER
    Drawing recovery.
    Drawing recovery log.
    Scanning completed.
    Validating objects in the handle table.
    Valid objects 10033 Invalid objects 0
    Validating objects completed.
    Used contingency data.
    Salvaged database from drawing.
    0 Blocks audited
    Pass 1 10000 objects audited
    Pass 2 10000 objects audited
    Pass 3 10000 objects audited
    Total errors found 720 fixed 720
    Regenerating drawing.

If the the drawing cannot be repaired, one of several messages is displayed to indicate that the file cannot be recovered. If the drawing is severely corrupted, the recovery process may lock up or AutoCAD may shut down. If this happens, you need to reboot the computer and try a different recovery method.

If the drawing can be opened with the RECOVER command, you should next use the AUDIT command. It is possible to have a drawing that contains "nested" damage that cannot be fixed by the RECOVER process on the first pass. In this situation, use the AUDIT process once or several times to fix this type of damage.

To begin, enter audit on the command line. You will be asked if you want the AUDIT process to attempt to fix any errors it encounters. Press the Y key to accept this choice and begin the AUDIT process. AutoCAD will now scan through the existing open drawing and attempt to find and fix errors. A report similar to the following report will be displayed on the command line (press F2 when the audit is complete to view the entire report):

    Fix any errors detected? <N>
    0 Blocks audited
    Pass 1 10000 objects audited
    Pass 2 10000 objects audited
    Pass 3 10000 objects audited
    Total errors found 16 fixed 16

If AUDIT finds and fixes errors, you should run the process again until no more errors are found.

Be aware that AUDIT may find errors that it cannot fix. Also, the audit process will sometimes report that it has found and fixed errors in the drawing, but subsequent audits will report finding and fixing the same number of errors. If this occurs, try to run the RECOVER process again or try one of the other recovery methods described in this solution.

Using the INSERT Command to Recover Drawings

It is sometimes possible to use the INSERT command to recover a damaged drawing. If the RECOVER command cannot successfully open a drawing, you may be able to insert the drawing into another drawing as if it is an external block.

To use the INSERT command:

  1. Start AutoCAD and open a new drawing. Be sure that you do not open a prototype drawing.
  2. Enter ddinsert on the command line. (You can also click Draw > Insert > Block.)
  3. In the Insert dialog box, click File, and then select the damaged drawing in the Select Drawing File dialog box.
  4. Clear the Specify Parameters Onscreen check box, and select the Explode check box.
  5. Click OK in the Insert dialog box.

AutoCAD attempts to insert and explode the damaged drawing. If the process succeeds, run the AUDIT command as described in the preceding section.

WBLOCK Command for Saving Parts of a Drawing

If you have a drawing that can be opened but AUDIT cannot fix, use the WBLOCK command to extract entities from the damaged file. This method is also good to use on drawings that become corrupted again even though the RECOVER feature was successful.

To use the WBLOCK command:

  1. Start AutoCAD and open the drawing.
  2. Set all of the layers in the drawing to ON, THAWED, and UNLOCKED.
  3. Enter wblock on the command line to create a new external block.
  4. In the Create Drawing File dialog box, enter a name for the block.
  5. Enter a name for the internal block (or press ENTER), and then select an insertion point.
  6. Select all the objects in the drawing by entering all on the command line or by manually selecting all of the objects using a crossing window.
  7. Close the current drawing after the external block is created without saving the changes and open the external block file.
  8. Run the AUDIT command on this drawing to test the file for corruption.

If running AUDIT on this drawing reports it finds errors, discard this file and reopen the original damaged file. The following discusses two methods for how to proceed. The first method should be used for a drawing that contains less than 30 layers; the second method should be used for a drawing that contains more than 30 layers.

Method #1 - For drawings with less than 30 layers

  1. Freeze all the layers in the drawing except for the first layer in the layer list and create an external block from the data on this layer.
  2. Open the external block file as described in the preceding section and perform an AUDIT.
  3. If AUDIT reports errors, discard this drawing, reopen the damaged file, and create an external block that contains only the data on the second layer in the layer list.
  4. Repeat this process until you have determined which layers in the damaged file contain corrupted data.
  5. Use WBLOCK to create an external block that contains all the objects on layers that do not contain corrupted data.

Method #2 - For drawings with more than 30 layers

  1. Set all of the layers in the drawing file to ON, THAWED, and UNLOCKED.
  2. Zoom to the drawing extents.
  3. Use the WBLOCK command to create an external block from all the objects in the upper right quarter of the screen area.
  4. Repeat this process for the other three quarters of the drawing.
  5. Open each quadrant drawing separately and run the AUDIT process on each.

    One or more of the quadrants will fail the AUDIT process.

  6. Divide these quadrants into quarters and repeat this process until you have identified all or many of the quadrants that do not report errors when audited.

    These quadrants can then be reassembled into a single drawing.

Drawing Recovery using DXFOUT and DXFIN

AutoCAD contains a translator for creating drawing interchange format (DXF™) files from DWG files. It is possible to use the DXF conversion process to fix damaged drawings. However, the DXF translator was not designed for recovering drawings, therefore this process will not work on drawings that contain a lot of damaged data. Also, the error and warning messages that are displayed during the DXF translation are not meant to provide detailed information about the status of drawing damage or recovery.

To use the DXF translator to recover a file, you need to open the drawing in AutoCAD and then immediately cancel the first automatic regeneration process that occurs when the drawing is opened. If you can perform this step, you can use the DXF translator to create a DXF file. You can then either re-translate the DXF file into a DWG file or repair the DXF file manually by editing it in an ASCII text editor, such as Microsoft® Notepad.

  1. Start AutoCAD.
  2. On the File menu, click Open.

    You can also enter open on the command line.

  3. Select the damaged drawing from the File dialog box to open it.
  4. In the Select File dialog box, click OK to open the drawing and immediately press the ESC key to cancel the current command. (If you are using MS-DOS® AutoCAD or if you have configured Windows AutoCAD as "Classic AutoCAD," you must press CTRL+C).

This process should cancel the first regeneration of the drawing. If the drawing can be opened, the AutoCAD command prompt will appear. (You may want to practice this process with an undamaged file to get a sense of how to do this.)

Next, enter dxfout on the command line. You are then prompted to enter a name for the DXF file and to specify the level of accuracy for the file translation. The translation process begins when the level of accuracy is entered. Refer to the AutoCAD User's Guide for more information about DXF files and translation choices.

After the DXF file is created, re-import the file into AutoCAD using the DXFIN command. To import the file into AutoCAD, open a new drawing (no prototype) and enter the dxfin on the command line and select the DXF file you created. The file is then translated again into an AutoCAD DWG file.

If the DXFIN process fails, you can view and edit the DXF file in an ASCII text editor. A DXF file is a complete translation of the drawing into ASCII text. Refer to the AutoCAD Customization Guide for a description of the contents and structure of a DXF file. If you prefer not to learn the structure of DXF files, you can scan the file for obvious anomalies or corruption, or possibly truncate or remove sections of the file in order to salvage some data.

Sources of Drawing File Corruption

As previously noted, file corruption can occur for a number of reasons. If you discover that you have a damaged drawing, it is important to track down and eliminate the source of corruption to prevent the problem from recurring. This section describes some of the most common reasons and recommends possible solutions.

Cause #1

A drawing can become corrupted because it is copied to a floppy disk or hard disk that contains defective sectors. Also, a drawing on a floppy disk or hard disk can become corrupted because the disk is damaged due to a power surge or other type of physical damage.

Solutions/Suggestions

Use the tools provided with the operating system, such as Scandisk (provided with Windows® and MS-DOS), to detect flaws in the physical media. Also, third-party diagnostic applications, such as Norton Utilities, can detect, and in some cases, prevent future access to damaged sectors on physical media.

Suggested drawing recovery procedures include the steps listed above. Also, files can sometimes be recovered from damaged physical media by computer hardware service providers.

Cause #2

A drawing can become corrupted because the system RAM is defective. When the drawing is edited in AutoCAD, the file is copied into and out of RAM and is not correctly written back to the hard disk.

Solutions/Suggestions

This problem usually manifests itself in other areas, such as corrupted operating system files or failure to run AutoCAD and other programs, before you experience corrupted AutoCAD drawings. If you encounter any of the following problems, you should check the integrity of the system RAM:

  • Drawings become corrupted
  • System terminates unexpectedly
  • Error messages occur in AutoCAD and other programs

Several third-party diagnostic applications, such as Norton Utilities, can detect flaws in system RAM.

Cause #3

A drawing can sometimes become corrupted if an AutoCAD session is terminated while the drawing is open in AutoCAD.

Solutions/Suggestions

Drawings are not easily corrupted while they are open in an AutoCAD. When a drawing is open and changes are made, the new or edited data is stored in temporary files. When a SAVE is performed, the information in the temporary files is written to the drawing database. If an AutoCAD session is terminated between saves, the data in the temporary files is lost, therefore, the drawing will not contain any of the changes from the current editing session. However, if an AutoCAD session shuts down unexpectedly during a SAVE operation, it is sometimes possible for the open file to become corrupted.

If AutoCAD shuts down unexpectedly, it is usually because of memory conflicts with other applications on a system, or a lack of system resources. If your installation of AutoCAD shuts down unexpectedly (even if drawings do not become corrupted), you should diagnose the problem by eliminating the possibility of a memory conflict or a shortage of system resources.

Cause #4

Drawings or DXF files from other CAD applications will not open in AutoCAD because of file translation problems.

Solutions/Suggestions

Files from other CAD applications will sometimes generate error messages when you open them in AutoCAD. In most cases, the application that created the file has not created the DWG or DXF file correctly. You should confirm the file is not actually corrupted by opening it in the original application and running the equivalent of the RECOVER command in that application.

In some cases a DWG or a DXF file created by another CAD package is meant to be used only with a specific release of AutoCAD. For example, a CAD application might only produce DXF files that can be opened in AutoCAD Release 12 and not Release 13. The documentation for the application that produced the file will generally provide information about compatibility with the various releases of AutoCAD.

Copyright e-tech.ca 2002-2010. All Rights Reserved. Sitemap.
E-Tech Corporation | E-Tech Data Recovery| E-Tech Research | Quickbooks Conversion | Quickbooks Connector | Quickbooks Recovery UK | Quickbooks Recovery Canada | Quickbooks Data Recovery

EMERGENCY RECOVERY SERVICE

Do you have a Corrupt Database or are unable to open a data file? We provide a recovery service that's guaranteed to repair your database. We have provided this service to big name companies like the US Army, American Express, AOL, AT&T, Air Canada etc. and you get the same guaranteed service. This includes telephone support if needed. We guarantee 100% satisfaction!

More info


PASSWORD AND DAMAGED FILE RECOVERY

We can recover damaged or corrupted data files and passwords from files of most formats. Please zip and FTP your file to us by clicking here.
You do not pay if we cannot recover your password or recover your damaged file.

More info


Testimonials

"Our client had a few access database that needed recovery since the workgroup file got corrupted. ETechRecovery's 'Remove Access Security' gave us access to all our databases without a problem. Also email support was great!" -- Van Rensberg, Icon Medialab

"Excellent software and support. I will not hesitate recommending E-Tech Recovery to all my clients" -- Gary Fischer, ACC