Trouble-shooting Hard Drive Problems - Part 1

It is extremely important not to make or write any changes to data on the hard drive without first verifying the hard drive configuration. Therefore, the first priority when unable to access information on a hard drive is to verify all of the configuration information dealing with the suspect hard drive.

Partition Parameter
Value or Equation

Partition Status
Bootable

Starting Head
1

Starting Sector
1

Starting Cylinder
0

Partition Type
Bigdos (drives greater than 30 MB), otherwise DOS 12

Ending Head
Total Number of Heads -1

Ending Sector
Sectors per Track displayed in Volume Boot Sector

Ending Cylinder
Number of Cylinders set in CMOS - 2

Total # of Sectors
Number of Sectors displayed in Volume Boot Sector

Start Absolute Sector
Number of Sectors per Track in Volume Boot Sector

Boot Signature
55AA

Step One: Make sure that Micro-Scope detects the hard drive

In Micro-Scope, System Configuration, Compare Settings - check to make sure that there is not an asterisk beside the number of hard drives detected value. If there is an asterisk, either the CMOS is set incorrectly, or there is an electronic problem (controller, cable, drive).

Step Two: Compare the BIOS parameters against the drive partition information.

In Micro-Scope, System Configuration, System Information - note the information displayed for the hard drive, specifically the parameters for the drive in question. Compare these parameters to the parameters in the MBR display under Micro-Scope, System Configuration, Partition Display using the following formula:

System Information
Master Boot Record

Cylinders
Ending Cylinder + 2

Heads
Ending Head + 1

Sectors
Sectors Per Track

If the information does not match, either the partition information is corrupt, or the CMOS setup or controller BIOS setup (if one exists) is incorrect, or there is a problem communicating with the drive.

Step Three: Check the drive functionality

In Micro-Scope, Diagnostics, Fixed Disk Tests - check the information in the Fixed Disk Selected window. Make sure that the proper drive type, model, and native parameters are showing in this window. If any of the information is incorrect, there is an electronic problem. Check the cable, controller and drive, re-seating all connections, and repeat the above procedure. After correcting the electronic problem, perform a read test on the first 10 cylinders of the drive. If any errors occur, then this is the most likely cause of the drive failure. Perform a read of the entire drive to determine if the errors are electronic in nature, or physical in nature. Electronic problems will result in the errors displayed not always being the same type or in the same location on the drive. If the problem is electronic, replace the cable, controller, and finally drive electronics and repeat the read test until no errors occur. If the error is physical, use an INT 13 type editor (such as Norton Advanced Editor), to block the entire drive and write the information to a daisy chained drive set to the same parameters as the faulty drive.

The next step, after the drive passes the read test on the first 10 cylinders, is to check the original partition setup of the drive.

Step Four: Check for the physical location of the master boot sector and the volume boot sector.

In Micro-Scope, Utilities, Fixed Disk Editor - use the FIND feature to search the last two bytes of each cylinder for a boot signature (55 AA). The first location where a boot signature should be found would be at cylinder 0, head 0, sector 1 (the master boot sector). The second location where a boot signature should be found is at cylinder 0, head 1, sector 1 (the volume boot sector). It is also possible to use the FIND feature to locate the volume boot sector by searching for MSDOS (in DOS based systems) or MSWIN (in Windows95 systems).

If there is a duplicate copy of the master boot sector found before the location of the volume boot sector, then it is possible that a boot virus has infected the hard drive in the system. The Rebuild Master Boot feature of Micro-Scope will eliminate any boot sector virus. Be sure to boot the system to the Micro-Scope diskette and immediately do a cold reboot of the system after using the Rebuild Master Boot feature.

If the volume boot sector is found in a location other than cylinder 0, head 1, sector 1, count the actual number of sectors before the volume boot sector, and compare that value to the value for the sectors per track displayed in the partition table described in step 2. If the values match, the most likely cause of the system failure is an incorrect CMOS setup. In this case the CMOS needs to be reset to the values indicated by the partition table described in step 2, remembering to use the formula described in step 2 when doing so. If the values do not match, set the CMOS Sectors Per track to the number of sectors counted before the volume boot sector and continue to the next step.

Step Five: Check the partition tables to make sure they are correct

Reboot the system to Micro-Scope and go to System Configuration, Partition Tables. Check the information displayed in the 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 in the master boot record, then perform step 2 again. If the information matches at this point, go to step 6. If the information does not match, then set the sectors per track in the Master Boot Record to the number of sectors per track currently set in CMOS, set the starting head to 1, starting sector to 1, and starting cylinder to 0, and write the information to the drive.

Step Six: Verify the Master Boot Sector information

Display the Volume Boot Sector and use the values for heads and sectors per track (on the right half of the screen) to perform step 2 again.

If the values match, then the volume boot sector is probably okay. If any values in the Master Boot Record do not match the table to the right, reset the values to match the values in the table, and write to the drive.

If the values still do not match, both the Master Boot Record and the Volume Boot Record are probably corrupt. At this point, e-mail Technical Support for help in this situation. Future articles will provide more insight into the repair procedure.

Step Seven: Check the FATs

Check to see if the first FAT starts on the sector just beyond the volume boot sector. Use the find feature in the Fixed Disk Editor to search for F8 FF FF in the first three bytes of each sector. The first occurrence should be on sector two of head one. Continue to search until the second FAT is found, indicated by the second occurrence of F8 FF FF. Note the location of the cylinder, head and sector of the second FAT.

Based on the start of the second FAT, and the start of the first FAT, calculate how many sectors are in the first FAT. If necessary, read each sector starting at the first sector of the first FAT, keeping a count of the sectors that have been read until F8 FF FF is seen in the upper left of the HEX display, which would indicate the start of the second FAT. After calculating the sectors per FAT, compare this value to the value in the volume boot sector. If the values match, the drive should be accessible through DOS at this point.

Step Eight: Attempt to access the drive

Boot to a DOS-bootable floppy diskette and attempt to access the drive. If the root directory and sub-directories on the hard drive are readable at this point, then attempt to boot to the drive. If the drive boots at this point, the problem has been corrected. If the drive is still not bootable, e-mail the 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 with the 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.

For more advice and free articles be sure to visit: http://www.micro2000.co.uk

---

Ten Things Everyone Should Know about Ordering an Inkjet Cartridge Online

It is true. You can save a lot of time... Read More

Choosing a Tape Drive

Tape drives remain the leading technology used by organizations for... Read More

Routing, Routed, and Non-Routable Protocols

ROUTING PROTOCOLSA generic term that refers to a formula, or... Read More

Computer Network Installation

Computer network installation has become an essential prerequisite for any... Read More

Testing Flyback Transformer - How to Test and When to Replace It

Nowadays, more and more monitor comes in with flyback transformers... Read More

Three Must Have Accessories For Notebook Computers

An Optical MouseNotebooks are normally equipped with touch pads which... Read More

An Introduction to HD-DVD

High density digital versatile disc is a digital optical media... Read More

Expansion Cards Part 3: PCI Express

In the first two installments of this series of Tech... Read More

Quality Recovery and Rework - When It All Goes Wrong

When Quality is the Target, but not the Result, what... Read More

Expansion Cards Part 1: (of a 3 part series)

PCIThe expansion slots available on motherboards allow for a variety... Read More

Laptop Security -Where?d My Laptop Go?

Laptops are lovely. They are convenient, mobile, powerful and prestigious.... Read More

Video Display

Video displays are most recent technique used in both outdoor... Read More

How to Add or Remove an IDE ROM drive

CD ROMS - If you're adding or removing an internal... Read More

Five Band Resistor Color Code-What Does The Last Band Of White Color Represent?

In electronic repair, most of the time i came across... Read More

Cisco CCNA Certification: Why You NEED Hands-On Practice !

CCNA and CCNP candidates hear it all the time: "you... Read More

How to Solve Multiple Paper Loading Problem in HP5L and HP6L Laser Printer

Have you ever encountered before the problem of having multiple... Read More

Ink Cartridges - A Humble Beginning

Computers and their accompanying printers were huge years ago. In... Read More

Ink Cartridges & Printing - Poor Print Quality Solutions

Why are there faint areas or gaps in my print... Read More

What Is A Fuse? And How To Test It.

A fuse is a very thin wire, which either melts... Read More

Unclogging Epson Print Heads

Tools needed:1 - 10cc Injector1 - 4" - 5" of... Read More

Setting up a Network -- Wired or Wireless?

To Wire or Not to Wire Wireless networks... Read More

Facing DVD Software Dilemma? Its Brainlessly Simple

The Pocket DVD Wizard allows you to make backup copies... Read More

DVD Recorders: Getting Started

IMO, these sd work 'like a VCR' as far as... Read More

The Making of Energy Efficient Datacenters

The Crooked E: The Unshredded Truth About Enron is a... Read More

Protecting Your Computer From Power Surges, Data Loss, Viruses, And Spyware

Protecting Against A Power Surge:Your computer is an expensive investment;... Read More

Trouble-shooting Hard Drive Problems - Part 1

It is extremely important not to make or write any... Read More

The Printer Cartridge Review

Years ago computers were huge and their accompanying printers were... Read More

Laptop Notebook ? Inexpensive Business Laptops

Laptop Notebook ? Your Portable OfficeIn much of today's business... Read More

Your Hard Drive is Going to Explode ? Why a UPS is Essential

It's most peoples worst computing nightmare. You wake up in... Read More

Computer Hardware Preventive Maintenance Software

Computers often break down at the worst of all times.... Read More

Learn to Find Cheap Laptop Computers on the Internet

Cheap laptop computers are coming to a store near you.... Read More

Emergency Response VSAT Internet Communications

As 2005 begins, there are a number of products on... Read More

High Definition DVD

High definition DVD, also known as HD-DVD (which actually stands... Read More