The Elektron folks didn’t say anything about that, but as the Octatrack works now, I cannot possibly imagine that they would have sent me a new power-supply board and then not honor the warranty after I successfully replaced it. I suspect that if I had fried something in trying to replace it, there might be an uncomfortable conversation afterward; but I didn’t.
Of course, your mileage may vary. I might well have said something to them that convinced them that I was a reasonable risk.