Fix BIOS settings not being saved

When starting the computer, I see error messages like:

Press F1 to continue, del to enter setup.
CMOS date/time not set.
Press F2 to run setup. Press F1 to load default values and continues.

Those are problems related to real time errors on the mainboard ( realtime ). Make every computer boot must press the above keys to enter windows. And you have to reset the time you can access the network, even though the network is still normal. Since the machine cannot save the date and time, save the settings in the BIOS. Please guide me how to fix the error of not saving BIOS settings.

Usually such errors are caused by a dead CMOS battery. This battery is used to feed the time and BIOS settings (even when unplugged). We just need to replace the new battery. Or you can use the VOM meter to adjust the 10v scale, put the black rod on the –  pole, the red rod put on the + pole of the battery and measure whether there is enough 3v or not. If enough, the battery is still good, not enough to replace the new battery.
If the CMOS battery is still there, then we remove the battery, use a razor to scrape the battery contact point on the mainboard and then attach it to test. Some mainboards are used for a long time, the contact points are oxidized, making good contact.

1. 

2. Check if the clear CMOS jumper jack is still jumping, see if it’s plugged in correctly. Mounting jumpers at pins 1, 2 is normal (normal) and 2, 3 is clear CMOS. Usually mounted in position 2, 3 will not power on.
   Check if 3-pin diode has 3v fed from CMOS battery? The CMOS battery anode provides 3v for a resistor (or coil) on the other end will give 3v for the 3-pin diode. To determine the 3-pin diode, we adjust the clock to the x1 scale, and 1 stick is placed at the positive pole of the battery, 1 rod is placed in the resistors, coils near the battery area. See the circuit (clock up to the end of the needle), then deduce the CMOS battery level 3v for that resistor. Also adjust the x1 scale, we find the diode by measuring on the other end of the resistor (the new resistor measures continuity with the + terminal, then we measure the non-connected end) to the nearby 3-pin diodes, which sub-circuit is that pin has 3v.
   If measured on a 3-pin diode without 3v, we will replace another diode.
   The 3-pin diode has 3v, then we proceed to reload the BIOS by going to the homepage to download the BIOS of that mainboard to load it with the loader. Or upgrade the BIOS in windows for the ASUS main I mentioned in the article: update bios ASUS .
   Finally, you proceed to solder or replace the IO chip. If not, then replace the southbridge with another chip. This circuit has 1 input to the IO chip and 1 line to the Southbridge chip.

   Those are the steps to fix the machine without saving the date and time due to the battery running out, unplugging the power, or the chip on the mainboard. Wishing you success.