I got the word tonight that it would be cheaper to buy a new computer than to fix my old one. That's the bad news.
Here's the good news: All the stuff that's on my old computer's hard drive can be transferred to the new one I just ordered from Dell, once I receive it. And I got a great deal: $400 instantly off, and free shipping. That special deal is no longer offered on the Dell website, but I had put it in my shopping cart a week or more ago, just in case, and when I ordered it tonight, they let me have the deal!
As I mentioned before, the old desktop is 3 1/2 years old, which is fairly old in computer years. Especially considering it operates in bad conditions in summer. Lots of dust and no air conditioning. And gets heavily used.
So, that's the scoop.