Try the below mentioned steps and check if this fixes the issue:
1. Press the Power Button and Check LED indicator.
2. If Power LED is not ON Connect the AC adapter to a known good power outlet.
3. Check Power LED indicator on AC Adaptor (without plugging into the Notebook).
4. If LED on the AC adapter is not lit (when unplugged from notebook), reseat brick and cable. If still no change, replace AC Adapter & Power Cord only, else follow next step.
5. If LED on the AC Adapter goes off only after connecting to notebook, replace Motherboard and DC-In port.
6. If the AC Adapter LED is ON after connecting to notebook, replace Power button only.
Please revert for clarification.