TazCat wrote on :
Success!! I received a new power supply from Ye Olde Mac Milt's Shoppe on eBay.
http://stores.ebay.com/Ye-Olde-Mac-Milt-s-Shoppe
The power supply cost $8 with an additional $8.50 in shipping. After installing it, the machine powered up normally and has been running for a couple of hours now. Looks like the power supply was the issue. Thanks for everyone's help!