One of my clients has an Inspiron 24-3455.  This one is setup for the bookkeeper.  She is only there once or twice a month.  The problem is that when she turns it on, it just sits there and won't boot.  This has happened more than once.  So, I went over and picked up the computer and have it in my possession. 

When I plugged it in at my house, it booted right up (albeit VERY slowly - thanks, Dell, for putting a lame 5,400 RPM drive in a desktop computer).  It installed a couple of updates and booted back up every time.  Just to try something different, I cloned the hard drive over to an SSD (boots WAY faster now, and programs open WAY faster, too).  I am currently running an extended test on the original hard drive.

I am at a loss at to what is causing the computer to not boot.  It will usually show the Dell splash screen, then it goes black and just sits there.  If anyone knows what I can check on this machine that might be causing issues, your input will be greatly appreciated.  Thanks in advance.

P.S.  The screen works just fine, so it is not a bad screen.  Like I said previously, it booted right up when I got it to my house.