I have two SSDs, one that I use now that works and my old one which I could not fix. When booting up my PC with the old SSD connected, the computer takes about a minute to get past the motherboard logo screen compared to ~3 seconds usually. When I booted from my good SSD with the bad one...
I would open command prompt and run "sfc /scannow". This should take some time. If it says everything is fine and no problems were fixed, run "chkdsk /f /r". Let me know how they go.