Previously working MC7455 suddenly a low-speed USB device?

I have a number of MC7455’s that have been working but suddenly assert themselves as low-speed USB devices after powerup. All devices were previously working as full-speed devices. Only the USB 2.0 interface is being used. Has anyone seen this behavior and, if so, how was it resolved?


How many usb port is enumerated?
E.g ls /dev/ttyUSB*

How about putting the modules to linux pc?

It never successfully enumerates in this condition - it doesn’t respond to the host’s USB packets.

Seems module is dead …

@DavidL, have you tried connecting the modems to another host, Linux PC etc?

Yes but it also fails to enumerate on other hosts.