XBOX 360S, disc and on button making sounds but console not turning on

Hiya, have been trying to revive my old XBOX 360 S after having not really played on it 2-3 years ago, tried to set it up on my TV that for reference also already has an XBOX Original 1st Generation plugged in and working. Essentially when I plug it on, my power brick is on orange, not damaged I don't think (I bought a replacement one off eBay which pretty sure broke instantly or was a scam). What's weird is that whenever I press the disc eject button and the on button for the console it makes sound, the beeps, but just doesn't turn on. I've had a look at what people have said online to help, the USB ports are clear, the prongs look fine and aren't touching each other which makes me think faceplate? I've read stuff about the power ribbon but I'm not exactly sure if that's the case. I'm not a big tech/repair guy, I've started to try and I guess open the console to have a look but I just don't want to do anything to wreck it. I'm asking here if there's anything I can do before having to either try to get a repair place to have a look at it and repair, or even just buy another on Ebay. Really looking to fix it because i've got games that aren't backwards compatible and that I'd like to play again and also to have a working trio of Xbox OG, Xbox 360 and Xbox 1.