Dell Inspiron 1521

Sounds like the power supply or motherboard is bad. You may find both on ebay. Replacement laptop motherboards are scarce, and some cost almost as much as a new laptop. You may want to buy a new one and save your old hardrive, and transfer the files over to the new machine. One other possibility is the hardrive. If you can disconnect your hardrive, and the machine posts, then you'll know it's bad. Fry's has a kingston 64 gb ssd drive for $109 good through tomorrow. I highly recommend this drive; works flawlessly and is virtually silent. If you want to spend less, they also have a wd 320 gb notebook drive for $54; both may be available at frys.com; you'll have to check.