Mac mini shuts down after a strange boot. What could it be?

Question

macOS

The Mac is connected to a monitor with built-in speakers. At some point, I brought the computer out of sleep and the music did not play. I turned off the monitor - the music started playing on the built-in mac speakers. But I put back the speakers in the monitor do not work. I decided to restart my mac as I rarely restart it. He hung. Just a gray screen and that's it. does not react. After some time, I turned it off forcibly through the button. At the same time, he opened the lid, looked whether it was dusty. I removed a little dust from above with a weak pressure of the vacuum cleaner.
I have already done this before 5 times.
I turn it on and see such a picture

After the bar is completely filled, mac mini cuts off (turns off) itself. After switching on, the same thing is repeated. I held shift, nothing happens, as far as I understand this is the safe mode.
Help, please, advice. Mb what links, what to read.
ps I googled a lot, but I did not find this problem.

Answer 1

Greetings! Try checking your hard drive for errors. To do this, run OS X Recovery over the Internet by holding down the Option-Command-R keys immediately after turning on or restarting the computer. Release the keys when the Apple logo appears. When the download is complete, the OS X Utilities window will appear. In the OS X Utilities window, open Disk Utility and use it to check your hard drive for errors.