I have a problem with Lenovo B750e. It randomly changing time and date (even when laptop have ac adapter pluged in) after restart. Date and time always is random. For example date is set on 18.02.2014 and after restart is 20.07.2017, and after next restart is 15.09.2020. RTC battery is working properly (replaced for a new one), no any post errors. Sometimes when I go to the configuration tab in bios it exiting bios automatically. Everytning else settings are fine (it not changing this things) but only date and time. From scheme I knows that RTC clock is on hybrid (Intel HM)... Someone have any idea or have similar problem?

check RTC xtal 32.768kHz

Did you mean x2101? I've already replaced it (2 diffrent xtal's) but nothing changed ;/ If someone have bios dumped for this model? I've already changed bios chip but I don't have dumped bios so I left old bios on it...

Someone has any idea with this laptop? It was made: reballing of hm65, replace x2101 for exacly the same, replace bios chip . The problem is still the same :( How do you think? Should I replace hm65 for brand new?

I've solved the problem. The HM65 was broken. After replaced for new one everithings OK. Thanks for help and have a good day.