Trouble-shooting Hard Drive Problems - Part 2

Written by Micro 2000 Inc


Continued from page 1

The drive now has a clean MBR and VBR, and with a few modifications torepparttar values stored in these data areas,repparttar 137274 drive will be fully reconstructed.

Accessrepparttar 137275 VBR inrepparttar 137276 Partition Editor. Some ofrepparttar 137277 values in this area will remainrepparttar 137278 same. These are: Bytes Per Sector, Reserved Sectors, Number of Copies of FAT, Max # of Root Dir. Entries, Media Description Byte, and Volume Boot Signature. Sectors Per Cluster may or may not need to be changed. Putrepparttar 137279 cursor over this value and press F1 for a formula that will help determinerepparttar 137280 proper value. Use this same F1 procedure for determiningrepparttar 137281 Total Number of Sectors. This value should berepparttar 137282 same asrepparttar 137283 value for Number of Sectors inrepparttar 137284 partition table.

The Sectors per FAT value equalsrepparttar 137285 number of sectors fromrepparttar 137286 beginning ofrepparttar 137287 first FAT torepparttar 137288 beginning ofrepparttar 137289 second FAT (as described inrepparttar 137290 first article in this series.) The values for Sectors per Track and Number of Hidden Sectors should be identical torepparttar 137291 values inrepparttar 137292 MBR. The Number of Heads is eitherrepparttar 137293 same asrepparttar 137294 value inrepparttar 137295 MBR orrepparttar 137296 same asrepparttar 137297 value ofrepparttar 137298 Number of Heads inrepparttar 137299 partition table plus one (refer torepparttar 137300 first article inrepparttar 137301 series for more information on this topic.) After completing this information,repparttar 137302 drive should either be bootable or accessible via a bootable diskette. If this is notrepparttar 137303 case, e-mailrepparttar 137304 Technical Support department for further verification ofrepparttar 137305 problem.

Reconstructing Multiple Partition Volumes

In some cases,repparttar 137306 drive may have been partitioned into smaller, logical partitions. If this isrepparttar 137307 case,repparttar 137308 chance of this data being corrupt is slim, and correct Head and Sector values are readily available from these areas. To findrepparttar 137309 second partition onrepparttar 137310 drive, userepparttar 137311 Fixed Disk Editor in Micro-Scope to viewrepparttar 137312 sector containingrepparttar 137313 "55 AA" string. This sector should appear afterrepparttar 137314 first VBR, so don't confuserepparttar 137315 two. The second MBR should start on Head 0, Sector 1 of a given cylinder. Accordingly,repparttar 137316 second VBR will appear on Head 1, Sector 1, andrepparttar 137317 FAT on Head 1, Sector 2, etc. By adjustingrepparttar 137318 first MBR in Micro-Scope so thatrepparttar 137319 value for Starting Cylinder, Head and Sector is equal torepparttar 137320 location ofrepparttar 137321 second MBR,repparttar 137322 VBR is now accessible throughrepparttar 137323 Micro-Scope partition editor. Use these values to reconstructrepparttar 137324 second MBR. The only value that will need recalculating isrepparttar 137325 Start Absolute Sector inrepparttar 137326 second MBR.

As outlined inrepparttar 137327 first article inrepparttar 137328 series,repparttar 137329 Start Absolute Sector isrepparttar 137330 same asrepparttar 137331 value for Ending Sector. This is notrepparttar 137332 case with a second partition. The Start Absolute Sector isrepparttar 137333 number of sectors prior torepparttar 137334 VBR. The formula forrepparttar 137335 Start Absolute Sector is as follows: (Number of Sectors) + (the Start Absolute Sector ofrepparttar 137336 previous partition) + (Sectors per Track). This formula will work for any additional logical partitions.

If, during partition reconstruction, there is something not understood, e-mailrepparttar 137337 Micro 2000 Tech Support Dept. before making changes torepparttar 137338 drive.

Disclaimer - The Micro 2000 Tech Tip is a free service providing information only. While we use reasonable care to see that this information is correct, we do not guarantee it for accuracy, completeness or fitness for a particular purpose. Micro 2000, Inc. shall not be liable for damages of any kind in connection withrepparttar 137339 use or misuse of this information.



Micro 2000 Inc has been helping to solve the day-to-day challenges that IT departments face in order to keep their businesses operational as well as profitable for over 14 years. The company's primary goal is to put the customer first - through feature-rich, simple-to-use IT tools that can help IT administrators manage their jobs more effectively.


Trouble-shooting Hard Drive Problems - Part 1

Written by Micro 2000 Inc


Continued from page 1

If there is a duplicate copy ofrepparttar master boot sector found beforerepparttar 137273 location ofrepparttar 137274 volume boot sector, then it is possible that a boot virus has infectedrepparttar 137275 hard drive inrepparttar 137276 system. The Rebuild Master Boot feature of Micro-Scope will eliminate any boot sector virus. Be sure to bootrepparttar 137277 system torepparttar 137278 Micro-Scope diskette and immediately do a cold reboot ofrepparttar 137279 system after usingrepparttar 137280 Rebuild Master Boot feature.

Ifrepparttar 137281 volume boot sector is found in a location other than cylinder 0, head 1, sector 1, countrepparttar 137282 actual number of sectors beforerepparttar 137283 volume boot sector, and compare that value torepparttar 137284 value forrepparttar 137285 sectors per track displayed inrepparttar 137286 partition table described in step 2. Ifrepparttar 137287 values match,repparttar 137288 most likely cause ofrepparttar 137289 system failure is an incorrect CMOS setup. In this caserepparttar 137290 CMOS needs to be reset torepparttar 137291 values indicated byrepparttar 137292 partition table described in step 2, remembering to userepparttar 137293 formula described in step 2 when doing so. Ifrepparttar 137294 values do not match, setrepparttar 137295 CMOS Sectors Per track torepparttar 137296 number of sectors counted beforerepparttar 137297 volume boot sector and continue torepparttar 137298 next step.

Step Five: Checkrepparttar 137299 partition tables to make sure they are correct

Rebootrepparttar 137300 system to Micro-Scope and go to System Configuration, Partition Tables. Checkrepparttar 137301 information displayed inrepparttar 137302 master boot record to see if there is any obvious corruption (that is, excessively large numbers, all partitions non-bootable, etc.) If there is no obvious corruption inrepparttar 137303 master boot record, then perform step 2 again. Ifrepparttar 137304 information matches at this point, go to step 6. Ifrepparttar 137305 information does not match, then setrepparttar 137306 sectors per track inrepparttar 137307 Master Boot Record torepparttar 137308 number of sectors per track currently set in CMOS, setrepparttar 137309 starting head to 1, starting sector to 1, and starting cylinder to 0, and writerepparttar 137310 information torepparttar 137311 drive.

Step Six: Verifyrepparttar 137312 Master Boot Sector information

Displayrepparttar 137313 Volume Boot Sector and userepparttar 137314 values for heads and sectors per track (onrepparttar 137315 right half ofrepparttar 137316 screen) to perform step 2 again.

Ifrepparttar 137317 values match, thenrepparttar 137318 volume boot sector is probably okay. If any values inrepparttar 137319 Master Boot Record do not matchrepparttar 137320 table torepparttar 137321 right, resetrepparttar 137322 values to matchrepparttar 137323 values inrepparttar 137324 table, and write torepparttar 137325 drive.

Ifrepparttar 137326 values still do not match, bothrepparttar 137327 Master Boot Record andrepparttar 137328 Volume Boot Record are probably corrupt. At this point, e-mail Technical Support for help in this situation. Future articles will provide more insight intorepparttar 137329 repair procedure.

Step Seven: Checkrepparttar 137330 FATs

Check to see ifrepparttar 137331 first FAT starts onrepparttar 137332 sector just beyondrepparttar 137333 volume boot sector. Userepparttar 137334 find feature inrepparttar 137335 Fixed Disk Editor to search for F8 FF FF inrepparttar 137336 first three bytes of each sector. The first occurrence should be on sector two of head one. Continue to search untilrepparttar 137337 second FAT is found, indicated byrepparttar 137338 second occurrence of F8 FF FF. Noterepparttar 137339 location ofrepparttar 137340 cylinder, head and sector ofrepparttar 137341 second FAT.

Based onrepparttar 137342 start ofrepparttar 137343 second FAT, andrepparttar 137344 start ofrepparttar 137345 first FAT, calculate how many sectors are inrepparttar 137346 first FAT. If necessary, read each sector starting atrepparttar 137347 first sector ofrepparttar 137348 first FAT, keeping a count ofrepparttar 137349 sectors that have been read until F8 FF FF is seen inrepparttar 137350 upper left ofrepparttar 137351 HEX display, which would indicaterepparttar 137352 start ofrepparttar 137353 second FAT. After calculatingrepparttar 137354 sectors per FAT, compare this value torepparttar 137355 value inrepparttar 137356 volume boot sector. Ifrepparttar 137357 values match,repparttar 137358 drive should be accessible through DOS at this point.

Step Eight: Attempt to accessrepparttar 137359 drive

Boot to a DOS-bootable floppy diskette and attempt to accessrepparttar 137360 drive. Ifrepparttar 137361 root directory and sub-directories onrepparttar 137362 hard drive are readable at this point, then attempt to boot torepparttar 137363 drive. Ifrepparttar 137364 drive boots at this point,repparttar 137365 problem has been corrected. Ifrepparttar 137366 drive is still not bootable, e-mailrepparttar 137367 Micro 2000 Technical Support department for help.

Disclaimer - The Micro 2000 Tech Tip is a free service providing information only. While we use reasonable care to see that this information is correct, we do not guarantee it for accuracy, completeness or fitness for a particular purpose. Micro 2000, Inc. shall not be liable for damages of any kind in connection withrepparttar 137368 use or misuse of this information.



Micro 2000 Inc has been helping to solve the day-to-day challenges that IT departments face in order to keep their businesses operational as well as profitable for over 14 years. The company's primary goal is to put the customer first - through feature-rich, simple-to-use IT tools that can help IT administrators manage their jobs more effectively.


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