Hi guys, I would really appreciate your advice. I've buy an SSD disc (ADATA SP550, 480GB) into my mid 2010 13' MacBook Pro. I've replaced them and made clean install of macOS Sierra from bootable USB flash disc. It was running perfectly, much faster than old HDD, I've made also TRIM of SSD through terminal. But after half an hour the computer has stuck and after restart it doesn't boot. I can see the apple logo and process of starting, but it shuts down almost immediately. I wanted to reinstall the macOS, but I can't even erase the SSD through the disk utility, computer see them, but I don't have access to them, and, if I want to install the macOS, there is not option to install them to those SSD. Thanks a lot!