Keyboard lights up but system won't start. Nitro 5 AN-515-55-57YK

I bought my son a Nitro 5 AN-515-55-57YK for school and gaming and it worked perfectly for 11 months, but then one day the screen went black while he was playing it and it no longer starts up, unfortunately there were two months between me buying it and giving it too him at the start of the school year, so it's out warranty and ACER want $250 upfront just to look at it, then there's postage on top of that, and then the cost of repairs or being told it's unfixable, so figure I may as well try troubleshoot it myself. I tried a local computer store but he was useless, and straight out told me to go buy a new one. When you turn it on the keyboard lights up, the fans run briefly and then stop but that's it, nothing else happens. We've tried the battery reset procedure for our model and it didn't work. I tried removing the battery and plugging directly into the power with it disconnected but still nothing. I've tried reseating both the RAM and the SDD. Can anyone please advise me on what could possibly be causing this and how to go about troubleshooting it? The day I took it to the computer store, it did actually turn on, but the guy hadn't plugged it in and the battery went flat before we could do anything, and then it wouldn't start up again. The only thing he told me, (other than to go buy a new one) was that because the light wasn't flashing it meant the hard drive wasn't working.


{Thread was edited to add model name to the title}