Major issue with ER8411....

Was running fine for weeks then suddenly my internet dissapeared.... logged into my OC200 controller and saw that the ER8411 was now disconnected so i went to check it out and whilst the ER8411 was still up and running, i noticed all of the led lights for the ports had all dissapeared (SFP+ 1 was connected to the internet, SFP+ 2 was connected to my TPLin 10G Fiber Switch).  Both ports were lit up previously, pulled the connections and re-inserted and still no light activity... tried plugging devices into the RJ45 ports and no lights come up.  Attempted to log into ER8411 and can no longer find that IP address on the network - ran IP scanners and device simpy appears to have gone bye bye so i cant even log into it to reset it.... tried manual reset method by olding down the reset button on device and absolutely nothing happens - not sure if im doing the hard reset wrong but no matter what i try it wont reset, its like its stuck frozen even after pulling the power....

Ended up resetting entire network and controller and started from scratch, got it all up and running and 2 hours later the ER8411 dissapeared again, same deal no port lights and can't get them to come back with a connection to my other devices... long story short i'm onto reset number 4 and the ER8411 keeps going AWOL....

Can anyone advise the correct hard reset for this device (I cant see how im doing this wrong but hey...just crazy the thing will not co-operate)

and anyone seen this issue before?  I'd previously had solid use out of it for 2+ weeks now and weird all of a sudden it just flakes out.