A:Answer UPDATE: Soon after I posted my question above, I bought a replacement power cord for my Schwinn 270 on Amazon.
It worked!... BUT only for a while. Three months later (on 4/02/22), I plugged in the bike and nothing happened. I'd assumed the original power cord that came with the Schwinn was faulty, but clearly something is wrong with the actual bike.
I'm so disappointed and worried that this isn't fixable — that I'm stuck with a non-working bike that i can't sell and out $$$. Any advice/insight would be appreciated.