Just because it looks clean does not mean that it is. Where the pins on the chips rub against the socket is where things go bad and lifting the chip and re-seating it fixes it in 99% of the case. This is an area that you can not see with your eyes unless you have 20X magnification built-in.

Both WayneStewart and Sherry Haibera are right. Too bad you got rid of the machine, because part of the "fun" of the hobby is solving your own problems when so called certified experts can't. How many A+ and MSCE tech out there can figure this out? maybe 1 out of 250,000. If that. If given some work this could have been a successful machine. At least it got video!

You need to take your time with this and you need to figure out the basics. The Apple II Schematics and repair guides are online so you can get it.