Cw80 transformer

It's likely something on your layout is shorting.  First unplug the transformer from the wall outlet/power strip.  Disconnect all track and accessory wires from the transformer binding posts.  Plug in/turn on the transformer and see if the Red light comes back on.  If it does, then you'll need to figure out what's causing the short circuit, either on the layout or in the wiring.  Often, the cause is something metal that's fallen onto the track touching the center rail and one of the outer rails.