Power saving mode has been designed in computers to save energy when there is no activity for a prolonged period or if the power source is not supplying power. In the case of laptops this could also be down to an empty battery. If users face a scenario where their laptop computers cannot exit from the power saving mode, then it is problem with the battery located on the motherboard. The only solution for this is to replace the battery with a new one and then restart the computer.
When you can't get a computer out of power save mode by any usual means, typically the cause is that the button-cell-type battery of your computer, located on the motherboard, is empty.
Usually, this happens on a computer which is a few years old since its batteries will have run out after such a long time. (The motherboard battery is used to store diffrerent settings when the PC power is off, such as date and time. When your PC detects this battery is empty, it will go into a low-power mode).
The solution is to replace the button-cell battery on the motherboard of your computer:
Open the case of your computer; Visually locate the motherboard (the main circuit board) of your computer; Visually scan for a button-cell battery (it looks like a watch battery but a little bit larger); Remove this battery from your computer;
Restart your computer: it should power up normally (you might have some warning messages during the start-up sequence, but ignore them); Set the date and time of your PC using the "Date and Time" control panel; You could now be able to use your computer normally but you will lose the date and time settings when you disconnect the computer power cord since there is no motherboard battery present to store them;
Take the motherboard battery to an electronics store and get a replacement, then install this new battery in your computer; Restart your computer and set the date and time again; the settings will now be saved using fresh motherboard battery power.
The power save mode of the monitor is designed to conserve energy when there are no or limited signals coming through. Laptop users sometimes may need to use an external monitor for display purposes. When connecting the laptop to this monitor, the latter may keep switching to power save mode. The most common reason for this problem is a faulty connection; as a result, the monitor will not receive any signals from the laptop. The solution to this problem lies in correcting the connection issue by checking the connecting cable.
If you are trying to connect your laptop to a monitor, and the monitor was working fine with a PC when you last used it, but now the monitor keeps going back to safe mode, you should check the VGA cable, it might be loose.
Press the Fn key and CRT/LCD key (F5 or F6 depending on your laptop model) to switch the screen.