routerOS reboot

Mikrotik It is reloaded in itself. And it not failure of a feed. As all the day all was normal, and in the evening constantly failure. What to do? On what to pay attention?

What hardware are you using?

Ive had Wrap boards with CM9’s do this.

celeron 667, 256Mb, 80Gb, 3-lan,(2 realteck, 1 3com)