4.All right, now our adapter is good, and it could output correct voltage. In this circumstance, unplug the power adapter from the laptop, and remove the battery, then holding press the power button to wait for about 1 minute, after that, plugged into the adapter and attempt starting on the laptop again.

5. Now, your test result is: the laptop still cannot start. Suppose the AC adapter was bad, if you decide to replace it with a generic one, you would have to follow the next rule:
the voltage output of your new adapter should be exactly same as previous one’s.
Such as 18.5V AC Adapter, you’d better only use it of 18.5V, and the amperage of your new adapter also should be the same or even a little higher, such as 3.5A, you should use 3.5A -4.9A.
If the measure above is useless, and the laptop is still at dead state, then probably motherboard gets something wrong, or DC power Jack has a problem. Actually the latter one stands a good chance, so the motherboard cannot get any power from the AC adapter. In this case, you’d have to disassemble the laptop and replace the DC power Jack. Please take a look at this article: