BanjoTodd

So follow up to my last post (in a nutshell bought dell optiplex 9020 off Facebook worked just fine then took hdd bay out plugged everything back in how it was before hen no boot error message then accidentally unchecked a box that said something like allow legacy settings at bootup or something then now I have no display at all) my power button and all the lights turn on, I replaced he cmos battery still no display, chnage the gpu or replace motherboard? I have no idea I need help

Where is it at

I know I probably should’ve been more careful

So I bought a dell optiplex 9020 off Facebook was fine and everything worked good for a couple days but then one day I was taking out the hdd bay to fit a graphics card in (realized wouldn’t fit anyway) then I got “no bootable device” error but then when I changed the boot sequence to Uefi or something like that and still boot error. I misclicked a thing that said something along the lines of “allow legacy boot up options” of that sort I unclicked it and no I don’t have a display

Honestly it's for why not and I don't know if adding more would cool down my gpu because it's about 75c if I'm playing graphic intense games

well i just want a couple more fans should I just get like 1 in the back to pull air out or should i bother putting some on top as well?

But it'd be pretty cool with the lights wouldn't it

So i wanna buy some cheap fans and on Amazon i found a cheap 5 pack of RGB fans for 35$ and I'd like to snazzy up my rig and also I currently only have 2 fans and wants things to be a little cooler. My rx580 is staying around 70s ish when playing games such as Apex Legends and i wanna cool down the whole system just a little. I am using a Fractal Design G case (i would take out the 2 existings fans to replace with the pack if i buy them so i can use all 5 colored ones) MSI Tomahawk B450 motherboard and a cx550w Corsair power supply The Fans I am looking to buy: https://www.amazon.com/gp/product/B07HCZ5WKJ/ref=ox_sc_act_title_1?smid=AFRUWVWO3UJ63&th=1

So I am planning on buying fans for my computer and I don't know if it'd work if i have the right hookups or anything because i watched a video of a guy connecting a fan hub with a 3 pin connector and I'm not sure my power supply has one? i looked and could find one unless it's connected already. The Fans I Plan On Getting: https://www.amazon.com/gp/product/B07HCZ5WKJ/ref=ox_sc_act_title_1?smid=AFRUWVWO3UJ63&psc=1 But Here's My Build: https://pcpartpicker.com/list/