The one long beep with three short beeps is a gpu error, if everything is working ok it sounds like you solved the problem.
According to the RVE10 Owners Manual, that means "No VGA Detected". So I guess your card was just not seated correctly and is why replacing it fixed the problem. See attached from the manual.
With my Asus VI Extreme Encore, I experience this randomly.
Sometimes It simply works, other times it'll beep.. 1 long, 3 short.
The system continues to load and windows appear. Anyone experienced this? LUL It's weird.