Reading BIOS Error Codes
Because beep codes can indicate only some of the problems in a system at startup, most BIOSes also output a series of status codes during the boot procedure. These codes are sent to an I/O port address that can be read by specialized diagnostic cards, which you can purchase from many different vendors. These POST cards (so named from the power on self test) feature a two-digit LED panel that displays the status codes output by the BIOS. The simpler POST cards are hard-wired to pick up signals from the most commonly used I/O port address 80hex, but more expensive models can be adjusted with jumper blocks to use other addresses used by certain BIOSes (such as Compaq).
These cards are normally sold with manuals that list the error/status codes. While the cards are durable, the codes can become outdated. To get an updated list of codes, contact the system or BIOS vendor's Web site.
Most POST cards have been based on the ISA bus, but the latest models are now being made to fit into PCI slots because ISA is becoming obsolete. For diagnosing portable systems, and to avoid the need to open a system to insert a POST card, Ultra-X offers a MicroPOST display unit that attaches to the parallel port. Contact Ultra-X at http://www.uxd.com/ for more information.
Onscreen Error Messages
An onscreen error message is often the easiest of the error methods to understand, because you don't need to count beeps or open the system to install a POST card. However, because some systems use numeric error codes, and even "plain English" codes need interpretation, these messages can still be a challenge to interpret. Because the video circuits are tested after components such as the motherboard, CPU, and BIOS, an onscreen error message is usually indicative of a less-serious error than one that is reported with beep codes.
Interpreting Error Codes and Messages
Because beep codes, error/status codes, and onscreen messages vary a great deal by BIOS vendor (and sometimes BIOS model), you must know what BIOS a system has before you can choose the correct table. With major-brand systems (and some others), you'll typically find a list of error codes and messages in the system documentation. You can also contact the BIOS or system vendors' Web sites for this information, or check on the CD included with Upgrading and Repairing PCs, 12th Edition.
BIOS Configuration Worksheet
BIOS configuration options vary a great deal, and incorrect settings can cause a system to fail, lose data, or not work correctly with PnP-compatible operating systems, such as Windows 9x/2000/Me. The following worksheet can be used to record the most critical BIOS configuration information. Use it when you are unable to print out the actual configuration screens.
System ID_____________________Brand & Model # ____________
Date Recorded_________________Operating System____________
Hard Disk Partitions______________________________________
Notes_____________________________________________________
__________________________________________________________
Standard CMOS/BIOS Configuration
(Configuration Option) |
(Settingcircle or write down setting used) |
Drive A |
1.44MB |
|
2.88MB |
|
Other__________ |
|
None |
Drive B |
1.44MB |
|
2.88MB |
|
Other__________ |
|
None |
1st IDE Drive |
Drive Type: |
|
Hard Disk |
|
CD-ROM |
|
Other (specify) |
|
_____________ |
|
Hard disk Geometry |
|
Cyl:_________ |
|
Sectors/Track: ____ |
|
Heads: ________ |
|
LBA Y/N: |
2nd IDE Drive |
Drive Type: |
|
Hard Disk |
|
CD-ROM |
|
Other (specify) |
|
_____________ |
|
Hard disk Geometry |
|
Cyl:_________ |
Standard CMOS/BIOS Configuration |
|
|
Sectors/Track: ____ |
|
Heads: ________ |
|
LBA Y/N: |
3rd IDE Drive |
Drive Type: |
|
Hard Disk |
|
CD-ROM |
|
Other (specify) |
|
_____________ |
|
Hard disk Geometry |
|
Cyl:_________ |
|
Sectors/Track: ____ |
|
Heads: ________ |
|
LBA Y/N: |
4th IDE Drive |
Drive Type: |
|
Hard Disk |
|
CD-ROM |
|
Other (specify) |
|
_____________ |
|
Hard disk Geometry |
|
Cyl:_________ |
|
Sectors/Track: ____ |
|
Heads: ________ |
|
LBA Y/N: |
Other BIOS Configuration Screens |
|
Boot Sequence |
1st drive: _____ |
|
2nd drive:______ |
|
3rd drive:______ |
|
4th drive:______ |
Anti-Virus or Write-Protect |
Enable / Disable Boot Sector |
PS/2 Mouse |
Enable / Disable |
Password |
Power On |
|
Password: ________ |
|
Setup |
|
Password: ________ |
External Memory Cache |
Enable / Disable (Level 2) |
Internal Memory Cache |
Enable / Disable (Level 1) |
Shadow RAM / ROM Shadowing |
Specify Range(s) In Use: |
|
_____________ |
|
_____________ |
|
_____________ |
|
_____________ |
USB Ports |
Enable / Disable |
USB Legacy Support |
Enable / Disable (keyboard & mouse) |
Memory Timing Configuration |
Auto / Manual |
|
If Manual, specify changes from system default below: |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
Power Management |
Enable / Disable |
|
If Enabled, specify changes from system default below: |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
Plug and Play (PnP) |
Enable / Disable |
|
If Enabled, specify changes from system default below: |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
|
_______________ |
LPT Port |
Mode Selected: |
|
Standard EPP ECP Bi-Di |
|
Disabled |
|
EPP Version # _______ |
|
IRQ: 7 5 _______ |
|
DMA for ECP Mode: _____ |
|
I/O Port Address: |
|
378H |
LPT Port |
Mode Selected: |
|
278H |
|
3BCH |
|
Disabled |
Serial (COM) Port 1 |
I/O Port Address: |
|
3FH (COM1) |
|
2FH (COM2) |
|
3EH (COM3) |
|
2EH (COM4) |
|
Disabled |
|
Notes: ___________________ |
Serial (COM) Port 2 |
I/O Port Address: |
|
3FH (COM1) |
|
2FH (COM2) |
|
3EH (COM3) |
|
2EH (COM4) |
|
Disabled |
|
Notes: ___________________ |
IDE Hard Disk Interface #1 |
Interface: |
|
Enable / Disable |
|
32-bit Mode: Enable / Disable |
|
PIO Mode: 0 1 2 3 4 |
|
UDMA Mode: 33MHz 66MHz 100MHz |
|
Block Mode: Enable / Disable |
|
# of Blocks: ____________ |
IDE Hard Disk Interface #2 |
Interface: |
|
Enable / Disable |
|
32-bit Mode: Enable / Disable |
|
PIO Mode: 0 1 2 3 4 |
|
UDMA Mode: 33MHz 66MHz 100MHz |
|
Block Mode: Enable / Disable |