So last evening after helping a friend transfer his components to a new Phanteks case, he decided to give me his EVGA Supernova 1050 G PSU
He said it "gave him trouble and turned on when it felt like" and he got fed up of it. It is pictured below:
 


So I take it and this morning I test it.

Plug it in to a motherboard and apply power, and the PSU Fan spins for a split second. I have to flip PSU switch off and on to repeat same.
Tried PSU on the "free power on self tester" that was in the original box. Same result. So it is confirmed faulty.

MY main question is, being the "second owner", which route is best for initiating an RMA? Regular route (register it first, but I have no original invoice), or the Guest RMA?
The PSU still has over 600 days of warranty left, based on serial, and it'd be a "low down dirty shame" to have to trash such a powerful PSU.