My Roon Nucleus is only a few months old. When I try to power it up the white power light flashes three times but the unit does not power up. I have tried the steps listed for other similar situations but nothing has worked.
In that case, if you’re sure the HDMI connection is good, either the M.2 drive, that the OS is on, went south or a component on or the motherboard itself has gone bad.
You’re still under warranty. If you bought it straight from Roon you need an RMA to get it fixed. If you bought it from a dealer, the next step would be to take it there.