Laptop shuts down randomly

you can use the unit without the battery. Remove the battery, plug in the charger/power supply and turn on the unit and wait for the result. if the problem persist?..... maybe the fault is in CPU fan. check the fan...overheating the processor. Cleaning the heat sync and reapplying silicon compound on CPU's can cure the problem.

try using a cooler pad for your laptop for heating issue,
try changing the RAM also sometimes the faulty RAM also does this

If it's left on for a period of time, specified by the power settings, it will dim the display, Hibernate, Sleep, etc. In the Control Panel, Power settings, Advanced Power setting , Change to High Preformance, adjust Hibernate and Sleep to Never, adjust advanced power setting to your specs. Shut down and unplug laptop , remove battery, when not in use, if you use on AC most of the time remove battery.

maybe it's a motherboard problem

I have seen the odd case where the power supply cannot keep up with the demands when the laptop is running causing it to shut down, but first! remove the main battery to see if that helps, no change! I recommend replacing the power supply adapter in hopes it will correct the problem. Go to www.ebay.com Type make and model of laptop, refine search to power supply and go through the list of prices.

It sounds like it's overheating, check your fans make sure all are working, if your fans are all working then your power supply is overheating and should be replaced. If your system is a laptop the battery can overheat also and shut the system down. So you can have different issues dependent on laptop to desktop.

Few reason for the shut down
Could be heat, electrical,

1. try cleaning all vents with compress air in order to remore dust and fuzz that can be cloging the vents.
Once this done, verify that fans works proprelly,(check air flow coming out of vents) if they dont they will need to be replace or cleaned out.

2. Check power supply unit, and battery.
Sometime power supply unit is defective, getting too hot and power output is not stable and shuts down the laptop. ( change power supply unit) check if battery hold charge. if not change battery

3. Check connections for looseness and contact

If all seems normal,and none of the mentionned point seem to be defective, the cause is deeper and would need to be looked at by a technician.

Hello, the major reason of laptop randomly shutdown is Overheating, you said it is not over heating...

I will suggest you couple of things that you can try:

1) remove the battery and plug the laptop on direct power supply, then place the laptop on a flat and hard surface and then boot the laptop.

or do a complete virusscan of the laptop.

or reinstall the OS...

Try taking out your battery it might be shorting out just run your laptop from the adapter and see how long it lasts before it shuts down

This problem might be occur due to old BIOS version installed on the laptop.
If your system shut down unexpectedly within 10-20 minutes while playing games or scanning the system which takes high cpu usages then the problem is of BIOS and try to install the new BIOS version.
for that visit the site of your laptop company.