Hello, need a bit of help I don't know much about audio stuff. At work we have PA Amplifier MA-181RU and there was always usb in it with music and it worked fine, today we took it out to put new music in and it worked great for couple hours and just stopped. Any idea why it doesn't detect usb anymore (sd card works but sounds so weird), I tried formatting it to FAT32 but no success, also tried with different usb drive, is there anything else I can try? is it possible there is number of songs limit or something or usb reader just died somehow? Thanks