We have a robot built and the program is fixed but for some odd reason after we downloaded the Firmware the external battery doesn't show up on the NXT anymore.

We don't have any power to our motors...plz help.

My guess is you might have a wiring problem. I remember our team having this problem too but it turned out that we had accidentally blown the 20A fuse that was connected to the battery so that's worth checking out. If it is blown you can just find a replacement at your local auto parts store.

we have 3 teams and 6 batteries, all of our stock fuses blew withen a few days of use, we have not had any problem with the replacements.