Matt,
The flashing power light is likely accompanied by a short whistle from inside the case. This is an indication that the power supply is trying to start up but can't. Normally, a 16 volt vs. 12 volt on a switching power supply is a big problem but you may be mixing AC and DC supplies as well. If that is the case then a 16 volt AC supply input could fry the power convertor in the external hard drive. Getting the drive out to see if it still works is the first thing you should do. If it spins up then get the data off it pronto. If the drive enclosure was very hot, then the drive could have been damaged as well. Excessive heat plays havoc with the precision components in the drive and might even change the size of the platter(s). When this occurs, the boot sector and formatted data tracks might no longer be read by the drive electronics. Should the drive turn out to be operating normally, then external drive enclosures are available for fairly cheap prices via the net or mail order from places like Microcenter and MCM (
www.mcminone.com)