I have a hp mini 311 1000nr, i was upgrading the hdd so i had it open upside-down next to the window on my dresser. the window was open and i didn't know it was raining and it got soaked so i immediately removed the battery and cmos, completely disassembled it and began to blow dry it, about 12 hrs later i power it up and it gave me a "cmos checksome is invalid" error but i still got it to boot, i set the time and configed everything but as soon as i reboot the time is reset to when it was made. "aug 16 2009".
I also noticed that the bios update i had done was erased, i tried to check the battery with an led but it wouldn't light up, idk if the led was good or not and i don't have a voltage tester.
I have also tried updating the bios but when i had it shut down for a while the update was erased again. i need to fix this because the old bios is not very good and does not utilize the hdd correctly, it lags on videos when the hdd is not active.
Just a side note the stock hdd used to also do this but when i updated the bios it stopped, so i know it does not have anything to do with the new hdd.
the battery that keeps cmos and bios alive while computer is turned off has died in your case (probably got shorted by the water). you need to find it on your motherboard and replace it. Hopefully that will be all of your troubles.
yea i replaced the battery with a smaller 2025 3v battery but it's still the same volts and the bios keeps the time but when it starts up it's ether behind or ahead even if i update the time it when i restart or get out of standby it's ahead or behind
i tested the battery i replaced and it can power a 3 volt led with no problem