Laptop not posting could be ram?

Hi

The laptop powers on hdd turns on for a sec then winds down they keyboard lights up and the CPU fan kicks in after a minute or two but screen is off.

So this is the 3rd time this problem occurred

First time I couldn't find a fix as I couldn't diagnos the issue

I was away for 90 days when i came back I took it to a technician who fixed it in like 2 minutes he said it was a bad ram stick which wasn't really the case because I reseated the “bad” ram stick and it worked.

Laop worked fine for about 9 months then it happened again. I took out the hdd reseated the ram and it worked now 6 months later the issue came up again this time

I took out the hdd tried it with both sticks on different positions even tried another ram stick but no results what am I missing here should I power cycle or something and if so how ?