Dell Inspiron 1545, black screen with flashing cursor

Hi, I have the dreaded black screen with flashing cursor on my Inspiron 1545 (from 2009).  Here is the order of events as to how this happened: The machine was acting funny, so I erased everything and reinstalled Windows, no luck, machine was still behaving oddly (slow, and crashing a lot).  I booted from a live Linux CD, which worked fine, no problems there.  Next, when I went to reinstall Windows again, it crashed, and wouldn't boot at all.  I get the Dell splash screen, and can get into config (f2) or boot order (f12).  It doesn't matter what I select, CD, USB, or HDD, it does nothing.  I turn it on, get the Dell splash screen, then the black screen with flashing cursor.  Nothing changes.  f8 does nothing either. Since the crash, I have tried the following: I have tried booting to my windows CD (Vista and 7, I even tried an old XP I had lying around), no luck. I have tried booting to a Linux rescue disk, no luck. I have tried booting to a Linux rescue USB stick, no luck I have tried booting to a Linux live CD, no luck. I tried removing the HDD, but just got an error, the unit still won't boot to the optical drive or USB at all. I reseated the RAM to make sure that was OK. The CD makes no sounds and the discs will not even spin up.  It is hard to tell, but I don't think the HDD is spinning up either. Any suggestions?  I'm stumped! Thanks for your help.