Hi everyone.
Yesterday we assembled new PC with the following configuration:

1) Intel Core i5-7400
2) Gigabyte B250-HD3
3) Kingston HyperX Fury Black 2133
4) Samsung Evo 850
5) Some chieftec power supply

The thing is that everything works fine in common. But when I enable fast boot in BIOS after reboot mobo returns 5 beeps and anyway continues loading but a little bit slower. Everything is working but why it beeps 5 time? When I disable fast boot, after boot everything works as it should-1 beep and loads even faster than with fast boot. I have already updated BIOS to the latest F7 version.
Maybe someone has the same mobo or knows something about this strange beeps or could check on similar mobo-why it beeps 5 times and doesn't return these signals with fast boot disabled? Just don't know-should I return mobo or it's just some nuance of this motherboard? If it was some hardware issue, I think it was alway beeping no matter fast boot enabled or disabled.
Thanks in advance.