Diagnostic for progressive failure: screen, track pad, boot failure.

Based on the research I've done here, it seems like a logic board failure, but I thought I'd share what's happening to see if there's anything I'm missing.

Yesterday the computer would boot and the only thing that was wrong was that the screen didn't work. I could hook it up to a monitor and use it as normal.

Today when I hooked it up to a monitor, it would boot up, and I could track the mouse around but could not click on anything.

I tried rebooting and it failed, getting to about 1/3 of the boot progress bar and rebooting.

Any help is greatly appreciated.