Thursday, November 27, 2008

PC Boot Problems

Beep Codes

The first thing that you’re computer will perform is POST (Power On Self Test), it tests the computers hardware insuring that it meets the necessary system requirements and that all hardware is working properly before starting the boot process. It later continues with additional tests (such as the memory test that you see printed on the screen) as the boot process is proceeding. If the computer passes the POST the computer will have a single beep (other computer BIOS manufacturers it may beep twice) as the computer starts and the computer will continue to start normally. However, if the computer fails the POST, the computer will either not beep at all or will generate a beep code, which tells the user the source of the problem.

What is Beep Codes?
Beep codes are the beeps you hear from the PC speaker when you turn on your computer. They are your computer’s way of letting you know what’s going on when there is no video signal or a bad memory or something rather serious goes wrong that your computer will start beeping. These codes are programmed into the BIOS of the PC. There is no official standard for these codes due to the many brands of BIOS there are on motherboards.

Pc Boot problems: (beep codes)

No Beeps - No Power, Loose Card, or Short.
1 Short Beep - Normal POST, computer is ok.
2 Short Beep - POST error, review screen for error code.
Continuous Beep - No Power, Loose Card, or Short.
Repeating Short Beep - No Power, Loose Card, or Short.
One Long and one Short Beep - Motherboard issue.
One Long and Two Short Beeps - Video (Mono/CGA Display Circuitry) issue.
One Long and Three Short Beeps - Video (EGA) Display Circuitry.
Three Long Beeps - Keyboard / Keyboard card error.
One Beep, Blank or Incorrect Display - Video Display Circuitry.

1 short - DRAM refresh failure
2 short - Parity circuit failure
3 short - Base 64K RAM failure
4 short - System timer failure
5 short - Process failure
6 short - Keyboard controller Gate A20 error
7 short - Virtual mode exception error
8 short - Display memory Read/Write test failure
9 short - ROM BIOS checksum failure
10 short - CMOS shutdown Read/Write error
11 short - Cache Memory error
1 long, 3 short - Conventional/Extended memory failure
1 long, 8 short - Display/Retrace test failed

1 short beep - Normal
2 short beeps - CMOS error
1 long and 1 short beep - RAM error
1 long and 2 short beeps - Video card error
1 long and 3 short beeps - Keyboard error
1 long and 9 short beeps - ROM error
Long continuous beeps - RAM not installed correctly
Short continuous beeps - Bad power supply or over heating