My Gateway MT3707 laptop fails to power on. Why?

My Gateway mt3707 laptop will not turn on.

I first started thinking it may be the ac power adapter had failed. So, I ordered a new universal adapter. It arrived in the mail and as soon as I plugged it in to the laptop I noticed the LED indicator on the front bezel lit up purple indicating the battery was charging. I pressed the power button and the laptop started with no problems. I had to leave at that moment and came back later that evening to work on transferring some files around.

I went to log in at the Windows log in screen and found the keyboard was not responding to any key punches. Then randomly I would get a few letters to punch. I guessed that the system needed a restart from sitting too long so using the mouse I clicked the restart command from the menu on the log in screen. I waited several minutes and the computer never attempted to restart. I figured the system had locked up even though the mouse was still moving so I pressed the power button to issue the restart command that way. Nothing happened. I then pressed and held the power button to turn off the laptop and still nothing happened.

I ended up removing the universal ac adapter and the battery to completely remove power from the system.

After a minute, I replaced the battery in it's slot and plugged the ac adapter back in to the laptop. No charge light indicator came on and the laptop would not power on. I removed the battery and the ac adapter again and let the laptop sit all night until the morning.

In the morning, I replaced the battery and also plugged in the universal AC adapter. The charging light for the laptop came on. I then checked the original ac adapter also. In the process of switching adapters, I noticed while the adapter was not plugged in to the laptop the charging light remained on.

And that details to where I stand now with my broken laptop. It is still plugged in, with the charging light still on. I have not attempted to turn the laptop on, yet, while I am seeking answers.

So far my best guess would be the motherboard or charging circuit has an issue? Is this laptop beyond repair?

It has been well over a week since I last attempted to mess with it. It never did power back on even after attempting to remove power, hardware, etc. So I will be buying a new laptop. Appreciate the answers that were given, though.