So I have a Lenovo Thinkpad laptop and it kept saying that my cmos battery was critically low. So I replaced it. But now it won't power on the screen. It just has a black screen. However, the F1 button , F4 button and fn button Never turn off and the power button blinks 3x and repeats continuously.
This has happened once before. Don't remember how it was fixed.
What can I do?
There is a hardware failure. The light patterns indicate a hardware issue.
Try this. Remove both cmos battery and the regular battery. On the botom of the laptop there will be a small hole. Place a paperclip into the hole and hold it there for thirty seconds. Put it all back together and try again. Look up emergency reset in your users manual if you cannot find the hole.