DS Lite won't come on. Red light blinks 1 time.

I have a DS Lite and the touch part of the lower screen quit working. I ordered a new touch panel and installed it as per some disassembly/reassembly instructions. Now when you flick the power switch, after about a 1 second delay, the light blinks red ONE TIME very quickly, and that's it. Nothing ever happens on either screen or anything. I opened it back up and checked all connectors (from lower screen, from touch panel, and from upper screen) to the main board. Any ideas on what would cause this?