I have a flite test power pack A on my tiny trainer. The motor used to work and then suddenly started making these sounds and not working. Sounds attached below.
https://drive.google.com/file/d/1Y1dnGOydZoZwvSE1exKuvRzsL7ZCn6ns/view?usp=sharing
https://drive.google.com/file/d/1Y1dnGOydZoZwvSE1exKuvRzsL7ZCn6ns/view?usp=sharing