I would look at replacing the motherboard, as it is the most likely cause. Now if you have another R610 you could try individually swapping out the devices on the minimum to post list from this server with a known good R610 and see if you can eliminate some of them as the cause, but I think you will confirm the issue lies with the systemboard.     
Hello, today i checked my R610 dell poweredge server, but when i checked it the panel show: "E1000 Failsafe voltage error. Contact support". It doesn't boot up and i've already tried with unplug and re-plug. What should i do?
E1000 Failsafe voltage error. Contact support R610