Just had the chance to listen to the attached MP3. Definitely not the Floppy Drive, but similar to the sound my 512Ke was making with the Floppy Drive disconnected.

Mine is a 220v version of the Analog Board, so the component layout is a little different and the solder joints on the Flyback may be a little different. However, considering the symptoms, I wouldn't rule out the solder joints on the Flyback as a possibility.