OK, you may have a different problem than what you thought you had.
We assumed it was a network problem when it could be a hardware problem.
Physically check the unit -
mark each disk with its slot position before removing them that way they go back into their original positions. Now remove the disks and check that there is no physical damage to them and their mounting sockets. If all is well clean out any dust and fluff before replacing the disks.
Now comes the hard bit, you need to test that the power supply is in fact supplying 12 volts @ 3 Amps. It is very possible for the power supply to supply 12 volts if there is no load but not when a load is applied. The initial boot sequence does not require much power but when the disks startup that is when the load is greatest and if the voltage drops to 10v or less things stop working.
We have seen too many power bricks that have been in use 24/7/365 without apparent problems fail when they have been switched off for some time and then switched on again (the problem, in those we have opened for inspection, is the capacitors have dried out and this changes their capacity and ability to work as designed).