It is common for people from non-technical backgrounds to be using computers these days, who often encounter hardware application problems. A common issue is exiting power saving mode. The computer enters power saving mode and the user cannot exit. In most cases, the problem lies with the motherboard's battery. To resolve this issue, the user needs to open the PC and locate the motherboard. After removing the battery, the system needs to be restarted. The reason the hardware was not responding is because the battery on the motherboard is old. After replacing it, the user can then exit and set their computer's time and date.
It might be a motherboard battery problem. It is unlikely to be the monitor because it is in power save mode. It is the PC itself. 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.