Thank-you, John I guess my first solution, therefore, is to replace it since I don't know how to test it. The machine is elderly by Iyo standards, sports 2 cd drives and 2 hard drives and has seen many hours of good use. BW ChrisF. ----- Original Message ----- From: John Ballance To: iyonix-support@xxxxxxxxxxxxx Sent: Monday, June 18, 2012 11:30 AM Subject: [iyonix-support] Re: Iyo drops router hi at this point.. the iyo power supply is PRIME SUSPECT. this ethernet misbehaviour is one of the earlier symptoms of a psu well out of spec.