Computer System Error Beep Codes

Power On Self Test Beep Codes

The computer POST (Power On Self Test) is the process of testing the computer system, insuring that 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 will have a single beep (with some 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.

Each time the computer boots up the computer must past the POST. Below is the common step a POST performs each time your computer starts.

1. Test the power supply to ensure that it is turned on and that it releases its reset signal.
2. CPU must exit the reset status mode and thereafter be able to execute instructions.
3. BIOS checksum must be valid, meaning that it must be readable.
4. CMOS checksum must be valid, meaning that it must be readable.
5. CPU must be able to read all forms of memory such as the memory controller, memory bus, and memory module.
6. The first 64KB of memory must be operational and have the capability to be read and written to and from, and capable of containing the POST code.
7. I/O bus / controller must be accessible.
8. I/O bus must be able to write / read from the video subsystem and be able to read all video RAM.

If the computer does not pass any of the above tests, your computer will receive an irregular POST. An irregular POST is a beep code that is different from the standard one or two beeps. This could be either no beep at all or a combination of different beeps indicating what is causing the computer not to past the POST.

Example of a Computer Error Beep Codes

Beep Code	Description of Problem
No Beeps	Short, No power, Bad CPU/MB, Loose Peripherals
One Beep	Everything is normal and Computer POST is fine
Two Beeps	POST/CMOS Error
One Long Beep, One Short Beep	Motherboard Problem
One Long Beep, Two Short Beeps	Video Problem
One Long Beep, Three Short Beeps	Video Problem
Three Long Beeps	Keyboard Error
Repeated Long Beeps	Memory Error
Continuous Hi-Lo Beeps	CPU Overheating

So as you can see if your computer doesn't start up and starts beeping away like a mime you can start the process of figuring out what is wrong by stopping for a second and listen to it. From a single beep which tells you everything is okay, to three long beeps which indicate a keyboard error to the siren like Hi-Lo beeps that tells you the CPU is overheating - listening to your computer is advisable!

IBM Standard POST Error Beep Codes

Beep Code	Description of Problem
1 short beep	Normal Post – system is ok
1 short beeps	POST Error – error code shown on the screen
No beep	Power supply or system board problem
Continuous beep	Power supply, system board, or keyboard problem
Repeating short Beeps	Power supply or system board problem
1 long, 1 short beep	System board problem
1 long, 2 short beeps	Display adapter problem (MDA, CGA)
1 long, 3 short beeps	Enhanced graphics adapter (EGA)
3 long beeps	3270 keyboard card

AMI versus Phoenix BIOS

When an IBM compatible computer is first turned on, the hardware runs a Power On Self Test (POST). If errors are encountered during this POST test, they are usually displayed via an Audio Beep or in a form of a code number flashed across the screen. This list of audio beep codes will help you determine the location of your problem, and enable you to move on to the next step of resolving the issue.

AMI BIOS Error Beep Codes

Beep Code	Description of Problem
1 Short Beep	One beep is good! Everything is ok, that is if you see things on the screen. If you don’t see anything, check your monitor and video card first. Is everything connected? They seem fine; your motherboard has some bad chips on it. First reset the memory module and reboot. If it does the same thing, one of the memory chips on the circuit is bad, and you most likely need to get another memory module since these chips are soldered on.
2 Short Beeps	Your computer has memory problems. First check video. If video is working, you’ll see an error message. If not, you have a parity error in your first 64k of memory. Fist, check your memory module. Reset them and reboot. If this doesn’t do it, the memory chips may be bad. You can try switching the first and second banks of memory chips. First banks are the memory banks that your CPU finds it first 64k of base memory in. You’ll need to consult your manual to see which bank is first. If all memory tests good, you probably need to change another motherboard.
3 Short Beeps	Basically the same thing as 2 beeps. Follow that diagnosis above.
4 Short Beeps	Basically the same thing as 2 beeps. Follow that diagnosis above. It could also be a bad timer.
5 Short Beeps	Your motherboard is complaining. Try resetting the memory and rebooting. If that doesn’t help, you should consider another motherboard. You could probably get away with just replacing the CPU, but does not cost-effective. Its just time to upgrade!
6 Short Beeps	the chip on your motherboard that controls your keyboard (A20 gate) isn’t working. First, try another keyboard. If it doesn’t help, reseat the chip that controls the keyboard, if it isn’t soldered in. If it still beeps, replace the chip if possible. Replace the motherboard if it soldered in.
7 Short Beeps	Your CPU broke overnight. It’s no good. Either replace the CPU or buy another motherboard.
8 Short Beeps	Your video card isn’t working. Make sure it is seated will in the bus. If it still beeps, either the whole card is bad or the memory on it is. Best bet is to install another video card.
9 Short Beeps	Your BIOS is bad. Reseat or replace the BIOS.
10 Short Beeps	Your problem lies deep inside the CMOS. All chips associated with the CMOS will likely have to be replaced. Your best bet is to get a new motherboard.
11 Short Beeps	Your problem is in the Cache Memory chips on the motherboard. Reseat or replace these chips.
1 Long 3 Short Beeps	You’ve probably just added memory to the motherboard since this is a conventional or extended memory failure. Generally a memory chip that is not seated properly causes this. Reseat the memory chips.
1 Long 8 Short Beeps	Display / retrace test failed. Reseat the video card.

Phoenix BIOS Error Beep Codes

These audio codes are little more detailed than the AMI codes. This BIOS emits three set of beeps. For example, 1 – pause – 3 – pause 3 – pause. This is a 1 – 3 – 3 combo and each set of beeps is separated by a brief pause. Listen to this sequence of sounds, count them, and reboot and count again if you have to.

Beep Code	Description of Problem
1 – 1 – 3	Your computer can’t read the configuration info stored in the CMOS. Replace the motherboard.
1 – 1 – 1	Your BIOS needs to be replaced.
1 – 2 – 1	You have a bad timer chip on the motherboard, You need a new motherboard.
1 - 2 – 2	The motherboard is bad.
1 – 2 – 3	The motherboard is bad.
1 – 3 – 1	You need to replace the motherboard.
1 – 3 – 3	You’ll need to replace the motherboard
1 – 3 – 4	The motherboard is bad.
1 – 4 – 1	The motherboard is bad.
1 – 4 – 2	Some of your memory is bad
2 - _ - _	any combo of Beeps after two, means that some of your memory is bad, and unless you want to get real technical, you should probably have the guys in the lab coats test the memory for you. Take it to the shop.
3 – 1 - _	One of the chips on your motherboard is defective. you’ll likely need to get another board.
3 – 2 – 4	One of the chips on your motherboard that checks the keyboard is defective. Motherboard needs replacement
3 – 3 – 4	Your computer can’t find the video card.
3 – 4 - _	Your video card isn’t working. You'll need to replace it.
4 – 2 –1	There’s a bad chip on the motherboard. Motherboard needs replacement.
4 – 2 – 2	First check the keyboard for problems. If nothing, you have a bad motherboard.
4 – 2 – 3	Same as 4-2-2.
4 – 2 – 4	One of the cards is bad. Try detaching the cards one by one to isolate the problem and replace the bad one. The last possibility is to buy another Mainboard.
4 – 3 – 1	Replace motherboard.
4 – 3 –2	See 4-3-1
4 – 3 – 3	See 4-3-1
4 – 3 – 4	Time of the day clock failure. Try running the setup program that comes with the computer. Check the date and time. If that doesn’t work, replace the battery, if not the power supply, you may have to replace the motherboard, but that is rare.
4 – 4 – 1	your serial ports are acting up. Reseat, or replace, the I/O card. If the I/O card is on the motherboard itself, disable them with a jumper or on it’s BIOS setup and then add an I/O card.
4 – 4 – 2	See 4-4-1, but this time is your parallel port that’s acting up.
4 – 4 – 3	Your math coprcessor is having problems. Run a test program to double-check it. If it is indeed bad, disable it, or replace it.
Low 1 – 1 – 2	Your motherboard is having problems
Low 1 – 1 – 3	This is an extended CMOS RAM problem; check your motherboard battery, and motherboard.

This Computer System Error Beep Codes is very essential since this will be also given in the TESDA Computer Servicing Exam. I suggest that you must review this as well.