There are several reasons present for this problem. First think from when this problem started. Applications are the first reason for this problem. So uninstall the apps. If problem has been happening after updating apps, then uninstall the updates. Software updates may be a reason for this problem. If this is the cause in your case, then go back to its previous version. Battery also causing this problem. Since, you told that you are using phone for 2 years, then battery may lose the capacity. So check it out with multimeter. Try factory reset after you get no result from all of the above methods. If factory reset didn't solve, then you would have to go service centre. Hope it helps!

Symptoms of a RAM Problem When you first turn on your computer it runs fine, but as you go about your business you notice that its performance diminishes. By lunch time, websites take minutes to load and local programs run at a snail's pace. This type of gradual deterioration of PC performance, especially with memory-intensive programs, may be caused by a RAM problem. Your computer randomly restarts while you are in the middle of something or freeze sporadically. It may also reboot almost immediately upon opening the desktop. This could be a sign of faulty RAM. A blue screen with white text flashes before restarting. Blue-screen errors are annoying because you don't even have a chance to read the error message. Bad RAM is one thing that cause them. Files—particularly ones you frequently access and save—seem to be inexplicably corrupted. RAM issues can lead to this problem, which can worsen over time. The file structure of your hard drive may slowly degenerate and you will no longer be able to boot your...

Is nothing showing up on your monitor? Fortunately, testing a monitor is one of the easier computer troubleshooting steps. By fully testing your monitor using a logical troubleshooting process, you can be confident that your monitor is or is not working properly and then take whatever action necessary to get back up and running. Testing a monitor could take from a few minutes to much longer depending on the cause of the problem   Picture of a blank computer monitor How to Test a Computer Monitor That Isn't Working Follow these easy troubleshooting steps to test your monitor: Check to make sure your monitor is on! Some monitors have more than one power button or switch—confirm that they're all switched on. Check for disconnected monitor power cable connections. Your monitor might be working fine and your only problem may be a loose or unplugged monitor power cable. Also be sure to check for any cable adapters that aren't fully secured, such as a small connector that joins an HDMI or DVI cable to a VGA plug,...