Light indicators not getting power / working randomly

[MitjaHD]

Most of the time on my lenovo thinkpad L590 the light inidcators on caps lock, num lock, esc, F1... are not lighten up, but the keys themselves work correctly. Sometimes the lights come on on their own and then die again after few seconds. It looks like they aren't getting power all the time. Other lights on laptop work fine. I don't know what I could try to do to solve this, it seems like a hardware problem.