Sony Vaio PCG-4121GL Troubleshooting

Device will not turn on when power button is pressed.

One possible cause of your laptop not booting could be due to a faulty power cord. Make sure that your power cord is both plugged into the the wall and into your charging port securely. It is possible that your power cord is faulty or damaged, in which case replacement cables are available for purchase online. It is important to get a charging cord that is made for the same model if you plan to buy a new one.

First power your device off, remove the battery and charging cord and then hold down the power button for 20 seconds. Afterward, put the battery in again and see if that changed anything. If your laptop is still not powering on and it still plugged into a viable power source, it is likely that your battery needs to be replaced. In this case, here is a replacement guide that you can follow.

One reason your laptop may not turn on or may unexpectedly shut down is because there is a problem with the motherboard. If the motherboard is broken you may experience a number of problems including your laptop being unable to turn on. The motherboard can be damaged from dropping the laptop, overheating, or the part simply getting old. If parts look burnt or broken then you know that the motherboard is the problem. You can take apart your laptop and check if everything looks fine. If there is visual damage it is recommended that you replace the motherboard.

Keyboard is visually dirty or parts are broken / unresponsive.

Start by making sure that the laptop is turned off. You can dip a cloth into soapy water and then make sure to wring out most of the water to prevent water from going underneath the keys. Afterward lightly wipe the cloth over the keyboard as well as the screen to remove dirt and fingerprints. Finally, go over the keyboard and the screen with a clean, damp cloth to remove the soap and then use a microfiber cloth to fully dry off the device.

If keys are physically damaged, replacements can be found online. If too many keys are damaged you may want to replace the entire keyboard. A guide for the keyboard can be found here.

If keys are not responding or only work when pressed from certain angles, you may want to look into replacing them. If too many keys are unresponsive you may want to replace the entire keyboard. A guide for the keyboard can be found here.

Data or files are lost without notice or reason.

Possible causes of failure for the hard drive may be due to unexpected device crashes, mechanical failure, or physical damage from excess heat or water. Check your fans and make sure your computer is receiving proper ventilation. Avoid spills or wetting the device. If none of these work to fix the issue than you may need to replace the hard drive. In the future, it is a good idea to backup important data on an external hard drive like a USB stick to make sure you can restore your files.

If your computer is not recognizing your previous hard drive when you start it up it is possible that it can be an issue with the copy of Windows. You should consider reinstalling Windows to see if that fixes the issue. If the issue persists you may need to replace the hard drive.

The computer will shutdown without notice.

One reason your laptop may not turn on or may unexpectedly shut down is because there is a problem with the motherboard. If the motherboard is broken you may experience a number of problems including your laptop being unable to turn on. The motherboard can be damaged from dropping the laptop, overheating, or the part simply getting old. If parts look burnt or broken then you know that the motherboard is the problem. You can take apart your laptop and check if everything looks fine. If there is visual damage it is recommended that you replace the motherboard.

If the power supply is faulty it can cause the computer to shut down. If there is a surge of power to the computer this can cause it to shut down. Make sure to only use chargers that are designed for the computer specifically as the voltage and currents that they supply need to conform with the battery. The easiest way to identify the source of the problem is to find another charger. If the new charger provides a charge, the old one was problematic, if the new charger still doesn’t supply a charge than the battery could be faulty and you will want to replace it.

Many computers are designed to shut down if the computer is overheating. This is a way to protect the components of the computer from failing due to the excessive heat. If your laptop is very warm when it shuts down then it is a heating issue. Refer to the section labeled “The Computer is Getting Very Hot”.

The computer is hot to the touch during use and programs begin to slow down.

Thermal paste is used to limit the amount of air pockets between important parts in the computer. If there is not enough present than the computer will be worse and transporting heat out of it and could overheat.

Make sure that the device is able to get good airflow as any small particle can block where air goes and cause heat build ups. A temporary remedy for this is with a bottle of pressurized air to blow out dust particles between the CPU and the heat sink. These can be purchased at a nearby hobby shop or online for a cheap price.