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    Windows Data Recovery- Professional

    Methods to Fix Computer Won’t POST Issue

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      Summary: POST or Power-On-Self-Test is performed by the computer to test the state of all the components required for it to boot seamlessly. In this handy guide, we will discuss why a computer won’t POST and various ways to fix the issue. We will also address a scenario where nothing but only a professional data recovery tool can recover your files lost due to this error.

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      The computer performs POST or Power-On-Self-Test when it is powered ON. This is performed to ensure that all the essential hardware required for booting up is working as intended. The POST is normally followed by a single beep indicating that the computer is ready to load BIOS.

      However, there are scenarios when the computer doesn’t perform POST and fails to load anything on the monitor. Moreover, this error is accompanied by various types of beep sounds or LED lights flickering on the motherboard. Let’s look at why a computer fails to perform POST on startup and what are the ways to fix it.

      What is POST?

      As mentioned earlier, POST or Power-On Self-Test is an operation that the BIOS initiates right after the computer is switched ON. During this, the computer tests various components that are required for its functioning. This test ends with a single beep sound, and after it, the OS gets loaded. The POST checks the main computer hardware and non-system board components. You can read more about them here.

      POST or power-on self-test sequence

      Why a Computer Won’t Perform POST?

      There are several reasons that could lead to computers not performing POST. Some of the reasons are listed down here –

      • Newly connected hardware
      • Bad or failed hardware
      • Improper or lose connections
      • Drained CMOS battery
      • Insufficient Power Supply Unit used

      What are the Signs of a Failed POST on a Computer?

      There are two ways to identify POST failure.

      • You will hear a beeping sound with irregular beeps. If your motherboard has LED lights, then they will be flashing in a pattern.
      • Your computer will fail to load OS after switching ON.

      How to Fix a Computer That Won’t Perform POST?

      POST is a critical operation, which determines if the components are in a workable condition, or not. If you have encountered either of the signs mentioned in the previous section, it means that the POST has failed. In that case, you can look at the methods ahead to figure out what went wrong and how to get the system to perform POST.

      Power-on self-test or POST


      • Before moving forward with the methods, make sure that the CPU’s internal components are compatible with each other. Once checked, proceed further.
      • Check your RAM. Improperly seated RAM modules or faulty or damaged contact pins could cause the computer to fail POST.
      • Also, check that all the cables are properly connected and nothing is loose.
      • Check the PSU or Power Supply Unit’s wattage and if it is sufficient for your computer or not.

      Method 1: Disconnect Newly Connected Hardware

      If you have recently connected some new piece of equipment with your computer and your computer has failed POST after it, it could be due to the new hardware. This is an easy way to diagnose and troubleshoot this issue, as sometimes, the hardware you have connected could be incompatible with your computer.

      remove peripherals to fix post issues

      Another thing to make sure of is if you have printers, joysticks, or other peripherals connected to your computer, they should be Plug and Play (PnP) enabled. Also, make sure that the drivers are up-to-date.

      Method 2: Remove USB Devices and Other Input Devices

      If there are multiple USB drives attached to your computer, then one of them could be the root cause of this problem. Disconnect all the devices, restart your computer, and check if it boots up properly without any error. Then start connecting each drive one by one until the computer fails to perform POST again.

      Method 3: Check your Monitor

      This is a very simple solution that everyone misses. You could have accidentally switched OFF your monitor by pressing the power button. So when you boot the computer, it boots up, but there is no video output, which becomes confusing. You can simply press your monitor’s power button to power it back ON and see if you are able to see the video output. Otherwise, check the monitor cables for any loose connections.

      Method 4: Diagnose Issues Using Beeps Codes

      Manufacturers use various beep codes to indicate a problem related to internal components like RAM, GPU, cables, etc. If your computer has failed POST and is generating random BEEP sounds, you can refer to the table below containing some general Beep codes. You can check your motherboard’s manual or manufacturer’s website to find more such codes.

      Method 5: Check/Reset CMOS

      A quick CMOS Reset is sometimes, the only solution that can fix your computer not performing POST. Refer to your motherboard’s manual to learn how you can reset the CMOS. You can also check by changing the CMOS battery.

      CMOS battery reset to fix post issues

      You can also try removing the CMOS battery from the motherboard and disconnecting the power cable from the AC source. Once done, press and hold the power ON button of your PC for around 30 seconds, and then put the CMOS battery back and connect your computer back to the AC power source. This should fix the issue with POST on your computer.

      What if the Computer Crashes After Booting Up?

      The above-mentioned methods should fix your computer and enable it to perform POST. However, if your computer boots up, is unable to sustain power, and keeps on crashing, it can lead to further errors or even data loss.

      If your computer has become unbootable after a crash and you are worried about your data, then you should not be, as there is a way to recover your data. In such a situation, a professional data recovery software like Stellar Data Recovery Professional can aid you in recovering your files and data from a crashed Windows PC.

      Stellar windows data recovery professional

      Its advanced data recovery algorithm and clean UI enable even novice users to easily recover data without much hassle. It allows users to not just recover data from any malfunctioned storage devices, but also any type of data lost from almost any storage device like HDD, SSD, SD Card, etc. Simply put, this software is a one-stop for any home user who wants to get their lost data back, in a few clicks.

      Final Words

      POST or Power On-Self-Test is a vital operation that a computer performs before loading the BIOS and the OS. While this operation ends with a single beep followed by the OS loading itself, sometimes, multiple beeps can be heard that indicate a possible POST-related issue with a computer. If a computer fails POST, it indicates issues with various components like RAM, GPU, CMOS etc.

      This guide addressed why a computer will not POST and how you can fix this by employing the methods discussed here in detail. And to leave no stone unturned, we also discussed cases where the system is rendered unbootable because of this issue and how to recover our data from a crashed or unbootable computer easily.


      Q. Why is POST Important?

      A. POST or Power On-Self-Test is a set of operations that a computer performs for checking that all the required components are working fine. A computer boots up only after it passes POST. Hence it becomes an important task.

      Q. Why is my computer not performing POST?

      A. Your computer not performing POST means that there is some issue with the components and connections. Check your computer’s cables along with all the components like RAM, PSU, CMOS battery, etc. It could also be due to the damaged power cable.

      Q. Why is my PC turning ON without performing POST?

      A. This could be due to incompatible components as they are majorly responsible for POST errors. Check all the cables, components and connections like RAM, Power cables, etc.

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      About The Author

      Keshav Katyal

      A passionate writer, driven by his interest in everything tech, Keshav Katyal has always been captivated by the latest gadgets since childhood. His interest in gadgets grew when he got his first gaming console, the Nintendo Game Boy Advanced. Hours and days of tinkering with gadgets encouraged the inner geek in him who now loves writing about the latest technologies.

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