My Dell Inspiron 3847 won’t turn on after upgrading the parts.

So I’ve upgraded my PC’s psu, cpu, and gpu. I’ve also removed the hard drive cage so I had room for my gpu. I made sure to remove all of the internals before drilling out the hard drive cage. After pressing the power button (to turn it on) the exhaust fan, and the gpus lights turn on briefly. The power button light also flashes orange . I’ve added a picture of the inside at the bottom. Here’s a list of my upgrades:

• PSU:

  CORSAIR CX750M 80 PLUS (750 watts)

• GPU: RTX 2080 ti (previously gt1030)
• CPU: i7-4790k (previously i5-4460)