- Sorting Hardware/Software/Configuration Problems
- Hardware Troubleshooting Tools
- Troubleshooting Power-Supply Problems
- Troubleshooting the System Board
- Troubleshooting Keyboard Problems
- Troubleshooting Mouse Problems
- Troubleshooting Video
- Troubleshooting Floppy Disk Drives
- Troubleshooting Hard Disk Drives
- Troubleshooting CD-ROM Drives
- Troubleshooting Tape Drives
- Troubleshooting Port Problems
- Troubleshooting Modems
- Troubleshooting Sound Cards
- Troubleshooting Network Cards
- Working on Portable Systems
Troubleshooting Floppy Disk Drives
Typical symptoms associated with floppy disk drive (FDD) failures during bootup include the following:
FDD error messages are encountered during the bootup process.
An IBM-compatible 6xx (such as, 601) error code is displayed.
An FDD Controller error message displays, indicating a failure to verify the FDD setup by the system configuration file.
The FDD activity light stays on constantly, indicating that the FDD signal cable is reversed.
Additional FDD error messages commonly encountered during normal system operation include the following:
Disk Drive Read/Write/Seek error messages appear.
The No Boot Record Found message appears, indicating that the system files in the disk's boot sector are missing or have become corrupt.
The system stops working while reading a disk, indicating that the contents of the disk have become contaminated.
The drive displays the same directory listing for every disk inserted in the drive, indicating that the FDD's disk-change detector or signal line is not functional.
A number of things can cause improper floppy disk drive operation or failure. These items include the use of unformatted disks, incorrectly inserted disks, damaged disks, erased disks, loose cables, drive failure, adapter failure, system board failure, or a bad or loose power connector.
Basic FDD Checks
If there is a problem booting the system, insert the bootable floppy disk in the new A drive and turn on the system. If the system does not boot up to the floppy, examine the advanced CMOS setup to check the system's boot order. It might be set so that the FDD is never examined during the bootup sequence.
If the system still does not boot from the floppy, check the disk drive cables for proper connection at both ends. In many systems, the pin-1 designation is difficult to see. Reversing the signal cable causes the FDD activity light to stay on continuously. The reversed signal cable also erases the Master Boot Record (MBR) from the disk, making it nonbootable. Because this is a real possibility, you should always use an expendable backup copy of the boot disk for troubleshooting FDD problems.
If the system has a second floppy disk drive, turn it off and exchange the drive's connection to the signal cable so that it becomes the A drive. Try to reboot the system using this other floppy disk drive as the A drive.
If there is a problem reading or writing to a particular disk, try the floppy disk in a different computer to determine whether it works in that machine. If not, there is most likely a problem with the format of the disk or the files on the disk. In the case of writing to the disk, you could be dealing with a write-protected disk, but the system normally informs you of this when you attempt to write to it. However, if the other computer can read and write to the disk, you must troubleshoot the floppy drive hardware.
Hardware troubleshooting for floppy disk drives primarily involves exchanging the FDD unit for another one that is working. If necessary, exchange the signal cable with a known-good one. The only other option with most PC-compatible systems is to exchange the system board with a known-good one.