I’m really 
someone can help with this issue. I got a bunch of older Maestro E206XT units that use the SL 9090 chips. However, while trying to update the firmware on 3 of these units, they became non-responsive. I’m guessing that the firmware update didn’t complete or is stuck on the update.
Does anyone have the knowledge/equipment on how to bring these units back to the land of the living? At my wits end.
Do you see DM port in the device manager?
Thank you for the quick response. I don’t have any debugging hardware or software available to me. If you (or someone else here) are/is familiar with this device and have the tools, I’m happy to send one to you if you’re willing to poke around and see you can get it working. Again, the chip is already on a PCB in a device (that’s actually really easy to take apart the casing).
maybe you can connect usb to windows and see what happens.