3 amber 5 white flash no display

Hi Dell. A colleague of mine had her Dell latitude 5420 not powering on. I am using the same model. So to try and determine if there are any issues with the battery and ram, I transferred them to my laptop. It didn't switch on. Now when I transferred back my original components, the laptop does not switch on, it only indicates 3 amber and 5 white flashes. There is no display but keyboard backlight turns on