Last Updated on April 27, 2026
There are few things more terrifying for a PC user than pressing the power button and getting a black screen accompanied by a strange sequence of electronic beeps.
When your computer refuses to boot into Windows 10 or Windows 11 and instead greets you with a series of beeps, it is performing a POST (Power-On Self-Test). Before the motherboard can even load your operating system or turn on your monitor, it has to physically check the hardware to make sure the processor, RAM, and video card are functioning.
Since the system cannot display an error message on the screen yet, it uses these audible patterns, much like Morse code to tell you exactly which hardware component is failing.
To use this guide, listen carefully to the number of beeps and note whether they are “short” or “long.” Most modern motherboards follow AMI or Award standards, but many brand-name PCs (like Dell, Lenovo, or HP) have their own unique patterns. Find your motherboard manufacturer below and match the code to diagnose your dead PC.
Phoenix BIOS Beep Codes
Phoenix BIOS uses a sequence of short beeps separated by pauses. For example, a “1 – 1 – 2” code means you will hear one beep, a pause, one beep, a pause, and then two quick beeps.
| Beep Code | What It Means | Possible Cause |
| 1 – 1 – 2 | CPU / motherboard failure | Defective CPU or motherboard |
| 1 – 1 – 3 | CMOS read/write failure | Defective motherboard |
| 1 – 1 – 4 | BIOS ROM failure | Defective BIOS chip |
| 1 – 2 – 1 | Timer failure | Defective motherboard |
| 1 – 2 – 2 | DMA failure | Defective motherboard |
| 1 – 2 – 3 | DMA failure | Defective motherboard |
| 1 – 3 – 1 | Memory refresh failure | Defective memory (RAM) |
| 1 – 3 – 2 | 64K memory failure | Defective memory (RAM) |
| 1 – 3 – 3 | 64K memory failure | Defective memory (RAM) |
| 1 – 3 – 4 | 64K memory failure | Defective memory (RAM) |
| 1 – 4 – 1 | Address line failure | Defective memory (RAM) |
| 1 – 4 – 2 | Parity error | Defective memory (RAM) |
| 1 – 4 – 3 | Timer failure | Defective motherboard |
| 1 – 4 – 4 | NMI port failure | Defective motherboard |
| 2 – 1 – 1 | 64K memory failure | Defective memory (RAM) |
| 2 – 1 – 2 | 64K memory failure | Defective memory (RAM) |
| 2 – 1 – 3 | 64K memory failure | Defective memory (RAM) |
| 2 – 1 – 4 | 64K memory failure | Defective memory (RAM) |
| 2 – 2 – 1 | 64K memory failure | Defective memory (RAM) |
| 2 – 2 – 2 | 64K memory failure | Defective memory (RAM) |
| 2 – 2 – 3 | 64K memory failure | Defective memory (RAM) |
| 2 – 2 – 4 | 64K memory failure | Defective memory (RAM) |
| 2 – 3 – 1 | 64K memory failure | Defective memory (RAM) |
| 2 – 3 – 2 | 64K memory failure | Defective memory (RAM) |
| 2 – 3 – 3 | 64K memory failure | Defective memory (RAM) |
| 2 – 3 – 4 | 64K memory failure | Defective memory (RAM) |
| 2 – 4 – 1 | 64K memory failure | Defective memory (RAM) |
| 2 – 4 – 2 | 64K memory failure | Defective memory (RAM) |
| 2 – 4 – 3 | 64K memory failure | Defective memory (RAM) |
| 2 – 4 – 4 | 64K memory failure | Defective memory (RAM) |
| 3 – 1 – 1 | Slave DMA failure | Defective motherboard |
| 3 – 1 – 2 | Master DMA failure | Defective motherboard |
| 3 – 1 – 3 | Interrupt controller failure | Defective motherboard |
| 3 – 1 – 4 | Slave IC failure | Defective motherboard |
| 3 – 2 – 2 | Interrupt Controller failure | Defective motherboard |
| 3 – 2 – 3 | RESERVED | N/A |
| 3 – 2 – 4 | Keyboard control failure | Defective motherboard |
| 3 – 3 – 1 | CMOS battery failure | Defective CMOS battery |
| 3 – 3 – 2 | CMOS configuration error | Incorrect setting |
| 3 – 3 – 3 | RESERVED | N/A |
| 3 – 3 – 4 | Video memory failure | Defective video card or memory |
| 3 – 4 – 1 | Video init failure | Defective video card or memory |
| 4 – 2 – 1 | Timer failure | Defective motherboard |
| 4 – 2 – 2 | CMOS shutdown failure | Defective motherboard |
| 4 – 2 – 3 | Gate A20 failure | Defective motherboard |
| 4 – 2 – 4 | Unexpected interrupt | Defective processor (CPU) |
| 4 – 3 – 1 | RAM test failure | Defective memory (RAM) |
| 4 – 3 – 3 | Timer failure | Defective motherboard |
| 4 – 3 – 4 | RTC failure | Defective motherboard |
| 4 – 4 – 1 | Serial port failure | Defective motherboard |
| 4 – 4 – 2 | Parallel port failure | Defective motherboard |
| 4 – 4 – 3 | Coprocessor failure | Defective motherboard or CPU |
| 9 – 2 – 1 | Video adapter incompatibility | Use a different brand of video card |
AMI BIOS Beep Codes
AMI (American Megatrends) keeps things simple. They use a straight sequence of short, rapid beeps. Count the total number of beeps before the sequence repeats itself.
| Beep Code | What It Means | Possible Cause |
| 1 Beep (No video) | Memory refresh failure | Defective memory (RAM) |
| 2 Beeps | Memory parity error | Defective memory (RAM) |
| 3 Beeps | Base 64K memory failure | Defective memory (RAM) |
| 4 Beeps | Timer not operational | Defective motherboard |
| 5 Beeps | Processor error | Defective processor (CPU) |
| 6 Beeps | 8042 Gate A20 failure | Defective CPU or Motherboard |
| 7 Beeps | Processor exception | Defective processor (CPU) |
| 8 Beeps | Video memory error | Defective video card or VRAM |
| 9 Beeps | ROM checksum error | Defective BIOS |
| 10 Beeps | CMOS checksum error | Defective motherboard |
| 11 Beeps | Cache memory defective | Defective CPU or motherboard |
Award BIOS Beep Codes
Award BIOS codes are distinct because they combine “Long” and “Short” sounding beeps, very similar to reading traditional Morse code.
| Beep Code | What It Means | Possible Cause |
| 1 Long, 2 Short | Video adapter failure | Defective video adapter (GPU) |
| Repeating | Memory error | Defective memory (RAM) |
| 1 Long, 3 Short | Video adapter failure | Defective video adapter or memory |
| High freq. beeps | CPU is overheating | CPU fan failure / Thermal paste issue |
| Repeating High, Low beeps | CPU failure | Defective processor (CPU) |
Standard IBM Post Beep Codes
If you are working on an older legacy system or an IBM server, you will likely encounter these standard post codes.
| Beep Code | What It Means | Possible Cause |
| 1 Beep (No video present) | Normal POST | Booting correctly (check monitor) |
| 2 Beeps | POST Error | Error code shown on screen |
| 0 Beeps | Defective power supply / board | Defective power supply or system board |
| Continuous Beeps | Power supply / board / keyboard | Defective power supply, board, or keyboard |
| Repeating Beeps | Defective power supply / board | Defective power supply or system board |
| 1 Long, 1 Short Beep | Defective system board | Defective system board |
| 1 Long, 2 Short Beeps | Defective display adapter | Defective display adapter (GPU) |
| 1 Long, 3 Short Beeps | Defective display adapter | Defective display adapter (GPU) |
| 3 Long Beeps | 3270 keyboard card | Defective 3270 keyboard card |
What if I don’t hear any beeps at all?
Many modern PC cases and high-end gaming motherboards no longer come with a built-in “Internal Speaker.” If your computer will not boot, but the system is completely silent, you will need to check for these modern diagnostic signals instead:
1. EZ Debug LEDs
Look closely at your motherboard for four small LED lights clustered together. They are usually labeled CPU, DRAM, VGA, and BOOT. When you turn the PC on, these lights will flash. If the startup process fails, one of those lights will stay permanently lit in solid red, white, or yellow. The lit LED tells you exactly which piece of hardware is causing the failure.
2. Post Code Display
Many premium motherboards have a tiny, two-digit LED screen directly on the circuit board. If your PC fails to boot, this screen will freeze on a specific alphanumeric code (like “00”, “FE”, or “A2”). You must check your specific motherboard manual to translate what that exact code means.
3. Install a Motherboard Beeper
If you are working on a custom build and your motherboard does not have LEDs or a digital display, check your motherboard box. Manufacturers usually include a tiny, black, circular speaker attached to two wires. You need to physically plug this into the four-pin “Speaker” header on your motherboard (usually located along the bottom edge) to hear the beep codes.
Pro Technician Troubleshooting and FAQ
Why did my computer start beeping after working fine for years?
Hardware moves over time due to “thermal creep.” Every time your computer heats up and cools down, the microscopic expansion and contraction can slowly push a RAM stick or a heavy graphics card slightly out of its slot. Dust buildup can also short out contact pins. The very first thing you should do when you hear a beep code is unplug the PC, open the case, and physically push down on your RAM and GPU to ensure they are seated firmly.
How do I fix a Memory (RAM) beep code?
If your motherboard indicates a memory failure (such as 3 short AMI beeps), you rarely need to buy new RAM right away. Unplug the PC, remove all of your RAM sticks, and gently rub a clean pencil eraser across the gold contact pins to remove any invisible oxidation. Blow out the RAM slots with compressed air, and reinsert just one stick of RAM into the primary slot. If it boots, turn it off and add the next stick.
What causes a continuous, non-stop beeping sound?
A continuous beep that never pauses almost always points to a catastrophic power delivery failure. This usually means your Power Supply Unit (PSU) is failing, or you forgot to plug in the supplemental 6-pin or 8-pin PCIe power cables into your graphics card during a new build.
Can a dead battery cause beep codes?
Yes. Your motherboard relies on a tiny, silver CR2032 watch battery to remember its BIOS settings. If this battery dies, your motherboard might forget how to communicate with your hard drive or CPU, triggering a CMOS configuration error (like the Phoenix 3-3-2 code). Popping out the battery and replacing it with a fresh one for three dollars can often bring a dead computer back to life.
Beep codes usually point to a hardware seating issue. If you have identified a RAM or Disk error through these beeps and successfully resolved it, check out our guide on using [Hiren’s BootCD] (Note: keep your existing internal link here) to run a digital stress test once you get the system back up and running!
Beep codes usually point to a hardware seating issue. If you’ve identified a RAM or Disk error through these beeps, check out our guide on Using Hiren’s BootCD to run a stress test once you get the system back up and running!
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