After a 48 hr nap, my computer came back to life. I was pretty happy, since I recovered all my work (backed up in a couple of places now!), and it seems to be functioning just fine, so I have working computer again. This is the second time a dead computer has come back to life, so I have probably used up all my luck. There was a funny thing going on with the screen this time, but after adjusting the contrast it has gone away (I won’t say has been fixed) and we are up and running again, just in time for another week of school work.