I was given a laptop from my oldest sister and there is a problem with it. When I turn it on, all the keyboard lights light up for 5 seconds and then it shuts down. I thought it was the CMOS battery but I'm not sure. Can someone please help me?
Why do you thin the CMOS battery is causing the issue? You could try resetting the laptop by removing the CMOS battery for a few seconds and trying to start again. Have you tried with cable and only with battery? I would recommend you to clean the laptop from dust and try starting with another power cable. If the issue persists, there may be some hardware problem and you should contact a technician.