so i had bought a new graphics card and new powersupply for a pc tower my friend gave me. When I upgraded them both on my computer tower, i pluggged it in and now it wont start at all. Not even the fans turn on. The power button blinks like 3 times and then never does it again until i unplug it for a bit and then plug it back in. Ive been trying to fix it for months but nothings has worked.
I have 8gb ram
gtx 1050 ti
amd 6300 6 core proccessor
and 500watt power supply

Small world. I am working on making a new post about such an upgrade to old gear and did use the 1050 Ti. Here's a link to that successful upgrade: https://www.cnet.com/forums/post/3ef4c495-10ec-4348-8dc1-1322367b0f7f/

The PC in that discussion has only a 320 or so Watt PSU and is very old. I used a P3 Watt Meter to be sure I'm not stress this PSU. Turns out it was never an issue with the 1050 Ti.

As to your PC it looks like the usual home built so I'd start smaller with the motherboard on cardboard to see if you can get a BIOS screen.

As always before we upgrade such we bring the BIOS to its latest before we change GPUs.
Also, since it looks home built we find many folk installed too many motherboard mounting pins and short out the motherboard. Always check for that.

I would make sure the connections from the power supply to the motherboard are all good - it is easy to have a poor connection on the 24 pin port. Especially if it is the "split" 20/24 pin type. Also, make sure the CPU power connection is good and see if the GPU needs a power connection. It actually sounds like the power supply is not getting a "power good" signal from the motherboard. You can buy a power supply tester very cheaply ($20 or so) that plugs in and checks all the voltages and signals. So: 1. Check 24 pin connection, 2: Check CPU power connection, 3: Check for properly seated Video card and RAM, 4: Check for PCIE power connection, 5: IF none of this helps, Remove everything from Motherboard but RAM and CPU, test it, add expansion card back 1 at a time (Power OFF and UNPLUG before adding each card!) to see when it stops working.

It happens because when we make changes in our motherboard while changing parts like - Graphics Card or RAM , we mistakely disturbs the otherwire this is why sometimes when we make changes in our motherboard and after doing all the thing when we turn on our PC nothing happen. I've also faced this problem when I was cleaning my CPU. You just try plugging all the ports again.