Since they replaced the DC jack, you probably have 2 choices. Either the adapter is going bad (try another Dell adapter). Or the problem lies in the motherboard. A problem that intermittent is hard to diagnose. Not knowing if the service provider ran diagnostics, run it yourself to see if any problems are detected. Restart the system and at the Dell splash screen start tapping F12. Select and run full diagnostics and watch for any errors. The fact that the light goes out usually means a short somewhere in the charging circuit. Again a bad adapter or MB since the jack is new. Check the jack though for a bent or missing centre pin.

Hi JOcean,

Thanks. Even without the adapter, the laptop intermittently works. The 2 scenarios I really recall is whenever I bring the laptop (twice already) in the service center building (air-conditioned place), the laptop turns on easily without the adapter. This is weird but I know the laptop should still be working in any condition and there supposedly be parts of the laptop that might be causing this. (causing static or flea power maybe)

I'll try running full diagnostics. By the way, the power switch assy was also replaced. So two parts were replaced.

Same problem as yours. Its now 2023! They replaced the motherboard twice already. Power is ok immediately after replacement but same problem returns after 2 to 3 days or after 5 on and offs. Im sick and tired, cant work because of this freaking laptop.