router 450G Lan ports stopped working

RouterOS Beginner Basics
1

hi everyone !
i got a problem with my router board 450G . LAN ports stopped working . when i restart the router , LAN ports lights then after a few seconds they are off . these are what i tried :

  1. tried different ports on a laptop , a pc and a modem ( LAN ports on all devices are working fine).
  2. tried different LAN cables on both devices .
  3. reset the router .
    LAN ports are still not lit , 2 days ago they were all fine . the router has not been damaged or getting any hit . there might be any firmware bugs or hardware damaged ?