Diagnosing Compaq Presario V6000 that charges yet cannot start


Every few months, I like to retrieve a Compaq Presario V6000 that I have had since the Noughties, though have not used as my primary computer since 2012. Going through Windows XP is fun and nostalgic, and I sometimes like to test older programmes for backward compatibility. Of course, I use it without any networking, for security. Despite being 15 years old, the computer was in perfect working order a few months ago.

Now, however, the computer is unable to turn on by pressing the power button, whether briefly (with an audible click) or pressing and holding. When its charging chord is connected, the socket lights blue as it ought, and the charging light at the laptop’s front turns on, showing that this is not a problem with the power supply. There are no cracks on the monitor, and when turning on, the power button and certain other lights on the computer’s top should turn on, so a broken monitor is not the problem. I replaced the battery recently, and it was able to charge fully overnight, so the battery is not at fault.

What should I do to diagnose the reason that this computer is no longer starting? I am very unskilled at solving hardware problems like this.