I didn't have a USB stick in when I powered it up. I haven't had a stick in for months. Just playing the instrument at night time on headphones. The unit was last out in Feb 2020 for church before the lockdown because of Covid. The unit is attached to a surge-protector and also has fresh AA batteries in the unit from November as a back-up. So why my unit went funky I have no idea. This morning I turned it on and it booted-up fine. Keeping my fingers crossed. If it does go on me I most likely will look at the Roland RD-88. I don't need it to run on batteries and the Roland unit has looks nice with all the sounds and built-in speakers. But I won't buy one without trying out the unit. If space wasn't a concern I would look at a Kawai MP7SE. Casio might get a look if they would update the PX5s unit.