Mikrotik hAP Lite RB941-2nD-TC reboots every 10 seconds

Brand new Mikrotik RB941-2nD-TC reboots every 10 seconds.
I tried to enter netinstall mode (pressing RES button) but it ignores it and keeps rebooting, so Netinstall does not see my router.
Is it hardware problem or what?
How to fix it?