The Lenovo T420i is always a hard reboot

1. Poor computer heat dissipation can easily cause the computer to automatically restart, because the CPU has a self-protection function, when the heat threatens the computer hardware, it will shut down and automatically protect itself, if this is the case, it is recommended to let your computer be placed in a dry and cool place, and ensure that it is clean, let the fan run normally, and ensure that the computer has good heat dissipation.

2. Secondly, there may be a problem with the computer software. This includes computer poisoning, as well as software conflicts or bugs. These may make the computer restart automatically, if you want to rule out software problems, you can first disinfect the virus, and then reduce the software running at the same time in the computer, tentatively run the software, see under what circumstances the computer automatically restarts, if you find the software that caused the restart, you can reinstall the system to try.

3. Computer reboot caused by other computer problems, including other computer hardware problems, such as hard disk bad sectors, etc., these problems should be tested by computer hardware test software. If there is a problem, you should go to a professional repair shop to repair it immediately.

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It is estimated that it is a memory problem, and it is best to fix it. Don't turn it on just yet.

LenovoT420The interface that appears as shown in the figure below is to directly select the startup item,Directly choose to boot from the hard disk,You can also directly restore the BIOS,This situation will not occur next time。

The steps to restore the default BIOS settings are as follows:

1. In the power-off state, connect the power adapter or battery, then find and press the Novo power button. As shown in the figure below:

2. Wait for the Novo Button Menu screen to appear after the computer is turned on, then select "BIOS Setup" in the list and press Enter;

3. Follow the above operations to enter the BIOS setup interface normally.

Causes and solutions:

Step 1: First of all, according to the specific situation analysis, if there is no power response directly, then check whether there is a power supply, poor contact, hardware and other problems, go to the second step, if it is not possible to enter the system may be operating system or software problems to go to the third step.

Step 2: Check whether there is a power supply problem, first see if the power supply is not plugged in well or there is a problem with the plug, if you are using a battery, then plug it in and try again. You can go to a friend or go to a computer repair shop or sales store to find the same model of power supply to try it.

After replugging the power supply, press the power button again, and if it still can't be turned on, then press it for a while. If you change someone else's power supply to turn on, it means that there is a problem with the power supply, if it proves that there is no problem with the power supply, it may be the hardware reason, go to the fifth step.

Step 3: Go to the last correct configuration to adjust, turn on and press and hold F8, enter the advanced options page, select "The most recent correct configuration", and press Enter. If it can enter the system, it may be caused by viruses, incompatible hardware drivers with the system, or operating systems.

After entering the system, run the anti-virus software, check and kill the virus, if there is a virus, restart the computer after the anti-virus, if it is not normal, it may be caused by the incompatibility of the device driver and the program, delete the graphics card, network card and other drivers, restart it after removing the driver, if there is still a problem, then go to the next step.

Step 4: Repair and install or reinstall the system, set "Optical Drive as the first boot device" in the BIOS, then insert the system disk, and press the R button to perform "Repair and Installation". If the fault persists, just at the beginning of the system, select "One-click GOST to restore the system" or use the system disk to reinstall the system.

Step 5: Check whether there is a hardware problem, disassemble the notebook to see if the hardware is loose, generally the hardware is not plugged in well, there will be an alarm sound, the long sound continues to sound that the memory module is not plugged in tightly, one long and one short means that the memory or motherboard has a problem, one long and two short means that the graphics card is wrong. If there is too much dust inside the notebook, it is best to clean it up first.

In addition, pay attention to whether it is caused by the new hardware, if it is normal before the replacement of the hardware, and it is not normal after the replacement, then check whether it is compatible. If it can't be started at this time, it is best to send it for repair, and the professional will check whether there is a problem with the hardware one by one.

There are many reasons why the machine can't be turned on, first, the system is damaged, the hard disk is damaged, the notebook can't recognize the hard disk, etc., second, the memory is broken or the memory slot is soldered, and then there is a problem with the motherboard power supply chip, and third, the BGA (north-south bridge, graphics card, network card, etc.) packaging chip virtual soldering damage will cause the boot screen not to light up. It should be a three-year warranty, free after-sales overhaul within the warranty, and answers to questions about notebook hardware.

There are a lot of problems, 1. The boot display is not on, 2. What is displayed when it is lit, etc.

Where are you stuck If you start it doesn't work If the power supply doesn't respond It may be out of power. Or if the motherboard is broken or something, go to the computer repair department and take a look.

The common reasons why laptops fail to turn on are mainly as follows:

1. The battery is damaged, when the battery is damaged, it will cause the battery to be unable to turn on, at this time, as long as the battery is removed and replaced with an external power supply, it can be used normally;

2. If the BIOS fails to refresh or is in the virus, it is also difficult to repair, so the BIOS should be removed and rewritten on a dedicated device.

3 Power board problems, there are many reasons for the power board problems, such as fuse blowout, control chip burnout, etc., because the chip of the power board chipset is relatively fine, there is a certain difficulty in repairing the chip, so many maintenance centers recommend replacing a new power board;

4.A file appears in the system, which can be resolved by reinstalling the system.

Upgrade the latest ThinkPad T420 BIOS

If there is no solution, you need to check with the official ThinkPad repair station.

Try out the problem with the power settings, or press the power button to start.

The reasons why the ThinkPad T420 laptop won't boot up are as follows:

1. Poor battery contact;

2. Computer system failure;

3. Caused by other hardware failures.

Solution: 1. Reassemble and install the laptop battery, and then turn it on;

2. Release the static electricity of the notebook first, and release the static electricity: remove the power cord and the external device of the mouse line light in the shutdown state, and remove the battery, press and hold the power button for 5 seconds, repeat 3 to 5 times, and then install the battery to turn on;

3. If it still can't be turned on, it is recommended to send it directly for repair and after-sales for detailed and comprehensive inspection and warranty processing.