Start with the simple things first. Those are normally the things most often overlooked (at least by me).

Now that you have the chassis reinstalled, make sure you have all the wires connected back where they are supposed to be: yoke wires, ground wires, neckboard connections, video input, etc...
Double check the caps you just put in to make sure they are all installed with the correct polarity and you didn't accidentally put one in backwards.
Is the fuse okay? Since the heaters are working, I assume so, but it doesn't hurt to check.
If all that looks okay, start going through this flowchart:
http://slot-tech-ftp.serveftp.com:8080/monitors/flowcharts/K7000flo.jpg to see if you can pinpoint the problem.