What are you running into the bumpers? Why would you cover them? If they are metal bumpers than you need to insulate one rail at least or better to insulate both rails. Most of my spurs dont have bumpers but ties crisscrossed over the rails in case I expand later.
The power cab has a built in breaker that shuts down in miliseconds. When you have a short its best to unplug the cab then fix the short then plug the cab back in.
Hope this helps
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Jeff But it's a dry heat!
You should be fine. Even though the LED might burn out. Are there any resistors in the bumpers? Have you tried the power cab yet? If it wont boot up you may have to take the bumpers off but I cant see a problem useing them.