Tuesday, 6 January 2015

Computer POST and beep codes

Computer POST and beep codes

The computer power-on self-test (POST) tests the computer to make sure it meets the necessary system requirements and that all hardware is working properly before starting the remainder of the boot process. If the computer passes the POST, the computer gives a single beep (with some computer BIOS manufacturers it may beep twice) as it starts up and 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.
If your computer has an irregular POST or a beep code not mentioned below, follow thePOST troubleshooting steps to determine the failing hardware component.

AMI BIOS beep codes

Below are the AMI BIOS Beep codes that can occur. However, because of the wide variety of different computer manufacturers with this BIOS, the beep codes may vary.
Beep CodeDescriptions
1 shortDRAM refresh failure
2 shortParity circuit failure
3 shortBase 64K RAM failure
4 shortSystem timer failure
5 shortProcess failure
6 shortKeyboard controller Gate A20 error
7 shortVirtual mode exception error
8 shortDisplay memory Read/Write test failure
9 shortROM BIOS checksum failure
10 shortCMOS shutdown Read/Write error
11 shortCache Memory error
1 long, 3 shortConventional/Extended memory failure
1 long, 8 shortDisplay/Retrace test failed
two-tone sirenLow CPU Fan speed, Voltage Level issue

AWARD BIOS beep codes

Below are Award BIOS Beep codes that can occur. However, because of the wide variety of different computer manufacturers with this BIOS, the beep codes may vary.
Beep CodeDescription
1 long, 2 shortIndicates a video error has occurred and the BIOS cannot initialize the video screen to display any additional information
Any other beep(s)RAM problem.
If any other correctable hardware issues are found, the BIOS displays a message.

Dell beep codes

Beep CodeDescription
7 beeps (repeated)Bad processor (CPU)
For other Dell beep codes, please refer to Dell's Beep Codes and PSA Diagnostics Chartpage.

IBM BIOS beep codes

Below are general IBM BIOS Beep codes that can occur. However, because of the wide variety of models shipping with this BIOS, the beep codes may vary.
Beep CodeDescription
No BeepsNo Power, Loose Card, or Short.
1 Short BeepNormal POST, computer is ok.
2 Short BeepPOST error, review screen for error code.
Continuous BeepNo Power, Loose Card, or Short.
Repeating Short BeepNo Power, Loose Card, or Short.
One Long and one Short BeepMotherboard issue.
One Long and Two Short BeepsVideo (Mono/CGA Display Circuitry) issue.
One Long and Three Short Beeps.Video (EGA) Display Circuitry.
Three Long BeepsKeyboard or Keyboard card error.
One Beep, Blank or Incorrect DisplayVideo Display Circuitry.

Macintosh startup tones

Error Tone. (two sets of different tones)Problem with logic board or SCSI bus.
Startup tone, drive spins, no videoProblem with video controller.
Powers on, no tone.Logic board problem.
High Tone, four higher tones.Problem with SIMM.

Phoenix BIOS beep codes

Below are the beep codes for Phoenix BIOS Q3.07 OR 4.X
Beep CodeDescription and what to check
1-1-1-1Unconfirmed beep code. Reseat RAM chips or replace RAM chips as possible solution
1-1-1-3Verify Real Mode.
1-1-2-1Get CPU Type.
1-1-2-3Initialize system hardware.
1-1-3-1Initialize chipset registers with initial POST values.
1-1-3-2Set in POST flag.
1-1-3-3Initialize CPU registers.
1-1-4-1Initialize cache to initial POST values.
1-1-4-3Initialize I/O.
1-2-1-1Initialize Power Management.
1-2-1-2Load alternate registers with initial POST values.
1-2-1-3Jump to UserPatch0.
1-2-2-1Initialize keyboard controller.
1-2-2-3BIOS ROM checksum.
1-2-3-18254 timer initialization.
1-2-3-38237 DMA controller initialization.
1-2-4-1Reset Programmable Interrupt Controller.
1-3-1-1Test DRAM refresh.
1-3-1-3Test 8742 Keyboard Controller.
1-3-2-1Set ES segment to register to 4 GB.
1-3-3-128 Autosize DRAM.
1-3-3-3Clear 512K base RAM.
1-3-4-1Test 512 base address lines.
1-3-4-3Test 512K base memory.
1-4-1-3Test CPU bus-clock frequency.
1-4-2-4Reinitialize the chipset.
1-4-3-1Shadow system BIOS ROM.
1-4-3-2Reinitialize the cache.
1-4-3-3Autosize cache.
1-4-4-1Configure advanced chipset registers.
1-4-4-2Load alternate registers with CMOS values.
2-1-1-1Set Initial CPU speed.
2-1-1-3Initialize interrupt vectors.
2-1-2-1Initialize BIOS interrupts.
2-1-2-3Check ROM copyright notice.
2-1-2-4Initialize manager for PCI Options ROMs.
2-1-3-1Check video configuration against CMOS.
2-1-3-2Initialize PCI bus and devices.
2-1-3-3Initialize all video adapters in system.
2-1-4-1Shadow video BIOS ROM.
2-1-4-3Display copyright notice.
2-2-1-1Display CPU Type and speed.
2-2-1-3Test keyboard.
2-2-2-1Set key click if enabled.
2-2-2-356 Enable keyboard.
2-2-3-1Test for unexpected interrupts.
2-2-3-3Display prompt Press F2 to enter SETUP.
2-2-4-1Test RAM between 512 and 640k.
2-3-1-1Test expanded memory.
2-3-1-3Test extended memory address lines.
2-3-2-1Jump to UserPatch1.
2-3-2-3Configure advanced cache registers.
2-3-3-1Enable external and CPU caches.
2-3-3-3Display external cache size.
2-3-4-1Display shadow message.
2-3-4-3Display non-disposable segments.
2-4-1-1Display error messages.
2-4-1-3Check for configuration errors.
2-4-2-1Test real-time clock.
2-4-2-3Check for keyboard errors
2-4-4-1Set up hardware interrupts vectors.
2-4-4-3Test coprocessor if present.
3-1-1-1Disable onboard I/O ports.
3-1-1-3Detect and install external RS232 ports.
3-1-2-1Detect and install external parallel ports.
3-1-2-3Re-initialize onboard I/O ports.
3-1-3-1Initialize BIOS Data Area.
3-1-3-3Initialize Extended BIOS Data Area.
3-1-4-1Initialize floppy controller.
3-2-1-1Initialize hard disk controller.
3-2-1-2Initialize local bus hard disk controller.
3-2-1-3Jump to UserPatch2.
3-2-2-1Disable A20 address line.
3-2-2-3Clear huge ES segment register.
3-2-3-1Search for option ROMs.
3-2-3-3Shadow option ROMs.
3-2-4-1Set up Power Management.
3-2-4-3Enable hardware interrupts.
3-3-1-1Set time of day.
3-3-1-3Check key lock.
3-3-3-1Erase F2 prompt.
3-3-3-3Scan for F2 key stroke.
3-3-4-1Enter SETUP.
3-3-4-3Clear in POST flag.
3-4-1-1Check for errors
3-4-1-3POST done - prepare to boot operating system.
3-4-2-1One beep.
3-4-2-3Check password (optional).
3-4-3-1Clear global descriptor table.
3-4-4-1Clear parity checkers.
3-4-4-3Clear screen (optional).
3-4-4-4Check virus and backup reminders.
4-1-1-1Try to boot with INT 19.
4-2-1-1Interrupt handler error.
4-2-1-3Unknown interrupt error.
4-2-2-1Pending interrupt error.
4-2-2-3Initialize option ROM error.
4-2-3-1Shutdown error.
4-2-3-3Extended Block Move.
4-2-4-1Shutdown 10 error.
4-3-1-3Initialize the chipset.
4-3-1-4Initialize refresh counter.
4-3-2-1Check for Forced Flash.
4-3-2-2Check HW status of ROM.
4-3-2-3BIOS ROM is OK.
4-3-2-4Do a complete RAM test.
4-3-3-1Do OEM initialization.
4-3-3-2Initialize interrupt controller.
4-3-3-3Read in bootstrap code.
4-3-3-4Initialize all vectors.
4-3-4-1Boot the Flash program.
4-3-4-2Initialize the boot device.
4-3-4-3Boot code was read OK.
two-tone sirenLow CPU Fan speed, Voltage Level issue