The CPU is the core component of your PC, any physical damage to it or a faulty chip could render your system unbootable. It may turn on, but you won’t get any display on your screen. The PC will not pass the POST test without a functional CPU. However, there are many reasons why this could happen.
Therefore, before you replace the CPU, we recommend that you take the necessary measures to check if the CPU is dead. Knowing if the CPU is dead before replacing it will also save you the cost of buying a new CPU chip.
Common things that can indicate a dead CPU
When the CPU dies, the system will boot and the fan will turn on, but the monitor won’t give any output. In some cases, the computer may not even turn on.
You will see all the signs mentioned below when the motherboard does not detect the CPU or if the motherboard has a dead CPU.
- The CPU RED light on the motherboard will light up
- Fans will run at their maximum RPM
- Black screen
- PC turns off automatically
How to know CPU is dead?
CPU chips rarely stop working. Bend CPU pins and physical damage are the two main reasons why your CPU is dead. If the pins aren’t bent and the CPU isn’t physically damaged, make sure you’ve tested the entire system before concluding that the CPU is dead.
Although the sign mentioned above may conclude that the CPU in your system is dead, there are a few other things you can check to see if the CPU is dead or not.
POST, or Power-On Self-Test, is the first operation the system runs after you press the power button. The test checks to see if the system detects every hardware component it needs. This includes CPU, RAM, GPU, and some I/O devices.
If the CPU is dead, it cannot communicate with the GPU. Therefore, the system will not have any display. The system will run, and the fans will spin, but you won’t see anything on the screen.
You can also try using POST cards on the expansion slots on your motherboard. The POST tag will display an error code. Using this code you can be sure if the CPU is damaged or something else.
Check out the Bent . Pins
CPU chips usually don’t break down over time. They tend to be slow as you use newer operating systems and apps. The only thing that can permanently damage the CPU is bent pins.
Remove the CPU from the motherboard and check if any of the pins on the CPU chip are bent. All pins must be parallel to each other. However, not all processors have pins that connect them to the motherboard.
Intel’s process won’t have any pins on them. So if you use an Intel processor, you may have bent the pins on your motherboard’s CPU socket. However, if you use an AMD processor, it is likely that you have bent the pins on the CPU.
Check fan RPM
The motherboard’s BIOS controls the CPU and case fan speeds when the system boots. The computer won’t be able to pass the POST test if it doesn’t detect the processor. And so the CPU fans will run at full RPM if the CPU dies.
Therefore, if you see the computer making a lot of noise, it is a sign that the motherboard is not detecting the CPU.
Replace the CMOS battery
CMOS stores information such as date and time, boot device, and data about all hardware connected to it. The CMOS battery powers the CMOS chip to hold all this data when the system is off.
If the CMOS battery dies, it can cause problems when starting the PC. Replace the CMOS battery to check if the PC boots.
Re-plug the power supply
The PSU can also fail when the motherboard doesn’t detect the CPU. The 8-pin power cable from the PSU connects to the motherboard. This cable supplies power to the CPU chip. A damaged 8-pin cable is believed to be the cause of problems like the motherboard not detecting the CPU. Plug this cable back in and start the PC to check if it passes the POST test.
If it doesn’t work, it could also be that the PSU is not providing enough power to the motherboard. Try replacing the PSU to check if it fixes the problem. If it still doesn’t work, do another test to see if the motherboard detects the CPU.
Remove and reconnect all wires
Sometimes internal wiring can cause abnormal operation in your PC. When the wire from the CPU fan is not connected properly, the fan will not spin. This will result in the CPU running at too high a temperature. As a result, the PC will randomly shut down. Besides, the cable from the PSU also needs to be secured.
Try removing and reconnecting all the wires to check if the motherboard detects the CPU.
Test CPU in another motherboard
Finally, if nothing works, remove the CPU from the current setup and install it in another system. If this system boots up, chances are the motherboard from the previous setup has failed.
However, if the new system still won’t boot, chances are high that the CPU is dead.
Can I run my PC without CPU?
The PC will not pass the POST test without a working CPU. Furthermore, since the GPU also needs to communicate with the CPU, without the CPU you wouldn’t have any display on your monitor.
Although the system may boot and the system/case fan may or may not spin, the screen will not show anything.
If your PC fails the POST test after performing all the steps mentioned above, your CPU may be dead.
However, before replacing the CPU, you should know that the CPU is not usually damaged or defective unless the pins are bent or have visible burn marks. Make sure you make sure the CPU is dead before replacing it.