It is the POST (power on self-test) is a set of processes that a computer goes through every time it’s switched on. It makes sure that all of the hardware of the system is operating properly prior to trying to load the OS. If the system does not succeed in POST, it won’t start.
If you’re encountering POST errors when you start your computer, these steps could help fix the issue.
Caution
The steps listed below will require you to remove physical parts from the computer. When working in the computer, it’s advised to be cognizant the dangers of ESD (electrostatic discharge) and the potential dangers it poses.
Remove new hardware
If you have noticed that any brand new hardware has been added to your computer, you should remove the hardware to ensure it’s not creating your problem. If your computer is working after removing the hardware, it could mean one of the following. It could be that the new hardware is unsuitable for your PC or a setting in your system needs to be altered or the hardware is not working properly.
Clean out any USB disks or devices.
Discard any disks CDs and DVDs which are on the computer. If there are any USB gadgets ( iPods, phones, drives, etc.) are connected, remove all of them. Reboot the computer to see whether anything changes.
Disconnect external devices
Get everything out of at the rear of your laptop computer with the exception of that power cable. Switch on the computer, and observe whether it sounds normal. If the computer hasn’t been heard from, ensure that the monitor or display on to check if any changes occur.
Check the power cords and reconnect.
If your computer isn’t receiving enough power or is being interrupted, the computer could have issues. Remove your power cables from your electricity strip as well as UPS (uninterruptible power supply) and connect your PC directly with a reliable electrical outlet in the wall.
Be sure to recognize the beep code
If you’re receiving the sound of a series of beeps, check out the page on beep codes to find a list of the various codes for beeps as well as their explanation. Also, examine your motherboard’s or computer’s documentation for more information about the codes that beep. These codes are intended to identify the component of your computer is malfunctioning or not working properly. If your beep codes are not listed, keep trying to figure it out.
Check all fans
Check that the correct the fans are on your computer. If a fan is not working (especially one that is the heating fan that is connected to the CPU) the computer might be overheating, or even detecting the failure of the fan which causes the computer to fail to start.
Make sure you have all cables checked.
Check that all cable connections connect securely to your computer and ensure there aren’t any loose cables by pressing firmly on each cable.
- All disk drives must be equipped with a data cable and a power cable attached to them.
- The power supply you are using should include at least one cable that connects into the motherboard. There are motherboards that may have cables attached to them that supply power on the cooling fans.
Connect all expansion cards.
If the recommendations above do not resolve the issue with the issue with the POST that is not working, remove from the riser board (if appropriate) and all expansion cards. If this solves the issue or permits the computer to send then connect just one card at one time until you can determine the card that is causing the issue.
Disconnect all drives
If you are unable identify the issue based on the beep sound (or you don’t hear a sound) turn off your computer. After that remove all cables such as IDE, SATA, SCSI, or any other data cable to the motherboard. When they’re disconnected try to restart the computer.
If this fixes your inconsistent POST, or if you get errors, connect each device until you know the device or cable that is causing the problem. In some cases it may be a loose connection to the cable that is causing the issue.
Remove the RAM
If you are still experiencing the same issue with the hardware that was removed, disconnect all RAM from the motherboard, and then switch on your computer. If the computer displays different beep codes or did not sound, but it is now, switch off your computer and follow the following suggestions. Be sure to shut off your computer prior to adding or removing memory. Then, turn it on again to see whether the suggestions resolve the issue.
- Re-insert the memory in that same slot.
- In the event that you own more than one memory stick take out all but one stick of memory. Then attempt to rotate through each memory stick.
- You can try one memory stick within each slot.
If you are able to get your computer to boot up with one or more memory sticks then you’re likely to be experiencing a bad memory. Determine the memory stick that is bad and then replace it.
If you are able to make the memory work in one slot, but it is not working in another slot, your motherboard may be defective. You could either fix the problem by running the memory into an alternative slot that will work or replacing the motherboard.
The computer is powered off.
In certain circumstances computers may experience problems with power, which are usually caused by an issue with the power source or motherboard. To determine whether this is the problem you can try switching the computer off or off and then it back on as fast as you can. Make sure that the computer’s power light turns between on and off. In certain situations you might be able to get your computer to start.
Reconnect the CPU and disconnect it.
If you’re comfortable working with their PC, they can replace it with the CPU by taking it out and inserting it back into the socket. It is also recommended to apply a new layer of thermal adhesive in between your CPU and thermal sink.
Loose BIOS chip
If your motherboard is equipped with the BIOS chip that is not working, it could be loosen over time because of the expansion of heat and lead to an inconsistent POST. Press gently to the BIOS chip to confirm that it isn’t loose.
Poor motherboard CPU, RAM, or power supply
If after trying all the suggestions above and you’re still experiencing issues it is likely that you have a defective motherboard or power supply RAM stick, or CPU. The next step is or replace these components or have your computer repaired. If you are planning to perform work yourself, recommend that you swap or replace components from a computer that is proven to function. Start by replacing the motherboard, followed by it’s time to replace the RAM and then the CPU and, finally, you can replace the electrical supply.