I'd imagine someone more familiar with electronics possibly could have figured out what specific component was wrong and replaced only that for an even smaller fraction of the cost.
Probably electrolytic capacitors (usually in the tens of cents each, or less.) They are the #1 suspect in any electronics as they have the most well-known and finite lifespan of all parts. They became particularly infamous for failing when this happened: https://en.wikipedia.org/wiki/Capacitor_plague
This was my assumption that it's a good chance that there was a failed capacitor. But at the time I didn't have a capacitance meter and I still don't have the confidence in soldering to be able to fix if that was the case.
Probably electrolytic capacitors (usually in the tens of cents each, or less.) They are the #1 suspect in any electronics as they have the most well-known and finite lifespan of all parts. They became particularly infamous for failing when this happened: https://en.wikipedia.org/wiki/Capacitor_plague
The term has even created a noun in other languages: https://sv.wikipedia.org/wiki/Kondensatorpest