This is intended to be a nearly exhaustive listing of every possible thing that could be wrong. Unfortunately, most PC
troubleshooting techniques are not for the novice PC owner. The large PC repair shop (ABI in Nampa, Idaho) will have
everything from a ROM burner, chip tester,diagnostic PCI cards, and volt meters/logic testers. You will not.
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It is hoped that you have a few very understanding friends that trust you and your diagnostic ideas. Because you will
often want to borrow almost his entire PC's components (the elusive working machine) to swap into yours. The idea is
to narrow things down so you don't lug 40 kilograms of metal around the block instead of a single card or something.
What exactly should a normal boot look and sound like?
Well, let me stress the importance of connecting at least four components to your PC every time you boot. You need a
speaker, a keyboard (not USB, unless supported by BIOS), a floppy, and a monitor. These four objects provide very distinct
qualitative output to the technician. For those of you who are familiar with the seven-step troubleshooting method, this is
step two - it comes way before you need to actually replace something.
- 1.First, LED's will illuminate everywhere - the mother board, the hard disks, the floppy, the case, the NIC, the
printer, the CD-ROM, the speakers, the monitor, and the keyboard.
- 2.The hard disks usually spin up, although some disks, especially SCSI's, may wait for a cue from either the
controller or may simply wait a fixed amount of time to begin spinning to prevent a large power surge during
- 3.The P/S and CPU fans will start to spin.
- 4.The first thing on the monitor should usually be either memory counting or some video card BIOS display. I
have had some video problems where the video BIOS only showed up about 30% of the time, and when it didn't,
the computer would usually lock up.
- 5.During the memory count, the PC speaker may click.
When the memory is done counting, the floppy disk often screeches as its LED comes on (called floppy seek).
- 7.The monitor may have messages from the BIOS, including BIOS version, number of CPU's, a password
prompt, and non-fatal error messages.
- 8.If there are any NIC's or other controllers with ROM, you should see a message from them at some point
during the POST.
At this point, the POST is done, and the boot begins.
The last part of the POST is often a chart that lists the components found during POST, like CPU and speed,
VGA card, serial ports, LPT ports, IDE hard disks, floppy disks, etc.
Usually, the C: drive is sought and will begin running the system files which used to be called the "bootstrap
program." If no system files are found, you may get a message from the BIOS saying, "Insert Boot disk and
press any key" or something similar.
Again, this is a non-fatal error, and you can put a bootable floppy in the drive and press a key.
If the above happens, you will know that your mother board is at least capable of running the ROM's POST. The
POST has many potential problems, most of which are non-fatal errors, however any consistent error is a cause
for a concern.
The fatal POST errors will normally generate no video, so you need to listen to the speaker and count beeps.
The number of beeps and their length indicate codes for the technician to use in repairing the PC. For instance,
removing the video card is usually a fatal error for most BIOS's, since the assumption is that you should have a
No RAM is a fatal error.
No CPU will generate no POST beeping codes, but it is, of course, a fatal error.
No keyboard is a non-fatal error, POST will complete, and you will be notified of the error.
Usually, it is something stupid like: "Keyboard Not Found. Press F1 to continue."
Here's a listing of POST error messages or Beep Codes that some of the major BIOSes generate during a
- No video or bad video during boot:
- Check the monitor's power and video connection.
- Try reseating the video card or putting it in a new socket.
- Make sure the speaker is connected in case you are getting a fatal POST message, which could have nothing to
do with video.
- Swap out the video card and/or the monitor.
Most notable and common POST messages are:
- 1.HDD (or FDD) controller error. Usually, this is a cabling issue like a reversed connector.
- 2.Disk Drive 0 failure. You forgot power to the hard disk, or you've got the wrong drive set in CMOS (run
Setup). Also make sure the disk is properly connected to the controller.
If the light stays on continuously after boot, you probably have the connector on backwards.
The Seven-Step Troubleshooting Method:
- 1.Identify the problem.
- 2.Perform visual and normal checks based on indications and operational knowledge.
- 3.Identify possible faulty functions.
- 4.Troubleshoot using diagnostic equipment, narrowing down the list of possibilities.
- 5.Identify the problem component.
- 6.Verify faulty component.
- 7.Repair, replace, document, and return equipment to original specifications. Theorize why the component
Ideas for random problems:
- Check the cables, check the cables, check the cables.
- Remove secondary cache, or disable it in Setup - this will surprisingly fix a plethora of problems.
- Under clock the CPU - it may have been sold to you at the wrong speed, a common scam.
- Replace SIMM's with someone else's.
- Replace the video card.
- Remove the unnecessary components like extra RAM, sound card, modem, mouse, SCSI card (if you have IDE),
extra hard disks, tape drives, NIC, or any extra controller card.
- Remove all hard disks and try booting from floppy.
- Remove the mother board from the case and run it on a piece of cardboard - this will fix a problem caused by a
mother board grounded to the case.
- Try someone else's cables.
- Recheck all the jumper setting on the mother board.
- Make sure you have selected the proper bus speed and clock multiplier for your CPU.
- Cyrix/IBM 6x86's always use a 2x multiplier (as of this writing) and are rated at a lower MHz than their P
Drastic plans (long shots and often expensive):
- Replace the battery used for the CMOS RAM and the RTC.
- Try someone else's power supply.
- Borrow someone's hard disk (just make sure you know his BIOS settings).
- Replace the CPU.
- Replace the BIOS if you are convinced that this is the problem.
- Ask your friendly BIOS vendor about whether getting a new BIOS will fix your problem.
- Or, if you know your mother board manufacturer, you should check their BIOS offerings to see if they have any fixes.
- Your last resort is to buy a new mother board.
Information for Windows XP only!
- If there is no partition marked active on the hard drive, the install disk boots from the CD automatically. This will result in the machine booting correctly from the CD once, then onto the hard drive the remainder of the time. Unfortunately, there isn't a way for the OS, Windows XP, to know how this boot BIOS is set before the OS boots for the first time. This is the cause of the multiple installation runs that can cause OS failure.
On the first install of Windows XP try to install with the BIOS set to only boot from the hard drive. If this does not work then setup the BIOS to boot from the CD-ROM. When the OS reboots when the installation is finished, enter the BIOS setup and set the hard drive to boot first.
- If you already have a failed installation or the OS system fails to boot
How do I blow away the MBR on my slave drive and get the whole thing back into a "virgin" state?
Here's one way to do that:
Boot from the Windows XP OS CD disk that you installed with.
At the screen titled "Welcome to Setup", choose "To repair a Windows installation using Recovery Console, Press R." (This should be the first screen you come to when booting from the CD.)
When prompted, enter 1 to select the installed OS.
Enter the Administrator password that you setup.
Please note the first line of each drive, especially the section including the total disk size, and the Disk number.
Example: The first 40GB hard drive should be somewhere around 40000 MB Disk 0. Your second 20GB hard drive should be somewhere around 20000 MB Disk 1. Once you have this data, press ESC to Cancel.
Note: Here is the command that will completely erase the drive, into a virtually irrecoverable state, make sure you want to do this before typing it.
Type: Mkdiskraw 1
(Where 1 is the drive number you want to completely destroy all data on. 1 should be the slave drive)
type: "y" if you have the correct number.
(You could also, at this point, use the same method to delete the first drive "0", should you be so inclined.)
The last resort to clean the hard drive would be to do a low-level disk format using utilities from your hard drive manufacture.
In either case, you will have to reinstall Windows.
When adding a second drive to a working system, we use the original drive's MBR to boot from, despite where we install to, or which drive is primary. If we then swap disks, install, and then re-partition we can then get into a state where we cannot correctly boot. (Blue screen Inaccessible boot device) or an error message similar to "Windows could not locate the system you are trying to load." Either of which could have the same cause. The boot.ini stores the disk ID and the partition ID for us. If that is located on the drive you clean, then the clean disk will not know where to boot the OS from. If you clean the drive the install is on, but not the boot files, we will essentially still have the same issues you began with: the OS drive having a 'wrong' drive letter, and being unable to format either of the partitions.