How to fix my preamp dilemma


My NAD integrated succumbed to old age and I found a Parasound Zamp3/Zpre2 combo on Ebay and pulled the trigger. Even this expenditure was somewhat controversial in my marital landscape, some people just don't understand audio fidelity doesn't grow on trees! For <$400, I couldn't have been happier, everything was great......but 8 months in the preamp started switching between channels and has a loud humming noise that seems like it's coming from the transformer, it powers on but is unresponsive.

From here I could use some advice from the knowledgeable, I'm not sure fixing the Zpre2 is money well spent, my first inclination was to find a used Zpre3, but there aren't any around. What seems more attainable at a reasonable price is a used Schiit Saga+, or an oldler Adcom, is it a bad idea to jump ship to another manufacturer given that the Zamp/Zpre are likely designed to function together?
sturdy
Do you have a guess at what that might cost? Not entirely sure what's wrong, but I can imagine it would involve a new power transformer. If it's gong to be over $200, I start to lean towards waiting for a used Zpre3, as I think it has sub outs, which the Zpre2 doesn't