This item was bought new - problems cropped up so soon, I assumed it couldn't be the new PSU. About 3 or 4 motherboards later it occurred to me to try another PSU.
 
Recently I tried powering up the EVGA430 PSU with a dummy load, all the rails came up, so I checked for ripple with an oscilloscope.
 
For one thing, my scope is too slow to show the true picture of the spike amplitudes, and secondly I don't know how much ripple is acceptable. My estimation is that on most rails the ripple is no more than about 25 - 30mV, but on one of the rails it looks to be at least 100mV.
 
It didn't look as if it was "wavering" as it would with mains ripple superimposed on the HF spikes - but I didn't specifically check for that. The big electrolytic capacitor(s) in the front end can fail - but its fairly rare.

When I have time, I'll dig out a faster scope and get a clearer picture of the ripple - its highly likely to be out of spec.
 
The EVGA430 was only a few months old so I assumed something else must be to blame for the emerging problems - by the time I'd swapped everything else out I was pretty fed up with it all and just shoved the EVGA430 on a shelf in disgust.

If you're still having issues with it, contacting phone support directly is the best and quickest option for getting a replafemrnt unit.

Notice I said phone support. 

So pass the buck to someone who can..................

Can't be bothered jumping through hoops - I'll probably just break it for spares to repair a PSU that's worth repairing and never buy EVGA products again.

A warranty service that advises you to sign up to a forum that can't do anything you mean.....................

ionfield
A warranty service that advises you to sign up to a forum that can't do anything you mean.....................

You're not listening... You can RMA without an account through the Guest RMA
OR while logged in, at the top of the page click Member and go to My Products where you can register the PSU and start an RMA.
OR call the Customer Service number here and ask you would like to RMA a power supply, and have your serial number and proof of purchase invoice ready if necessary
Stop being unnecessarily bitter over it and do one of these 3 methods, or learn to live with your problems. Either way, suck it up and quit whining. You could've already had your replacement on the way.

Clicking the "Guest RMA" link posted by mike406 just opens another iteration of this thread.
 
Round here; that's what we call getting the runaround................

Not sure why you are having these issues. Please make sure that you have the product registered at EVGA.com > Support > Product Registration.  And Call 888-881-3842, and we can help you with setting up an RMA on that product.

The item is at a different location to the internet PC, so I'll have to gather all the information to do the registration.
 
Its sat on a shelf quite a while - I was pretty cheesed off with it all after trying several motherboards because I couldn't believe a few month old PSU was causing all the problems.