Picking up a Defender cab tonight. I looked at it last night and it looked to be complete except the back door. It's a little rough but a good starting point. We did not plug it in but he said it's dead and doesn't do anything when you power it up. The safety switch for the back door looked like it was taped over to keep it engaged while the door was removed. Hoping that switch has crapped out or is not fully engaged by the tape guess we'll find out tonight when I get it home. All my experience thus far has been MAME cabinets, very comfortable with computers no problems there. This is my first shot at trying to repair/restore an actual arcade cabinet. If you can point me to some good resources for testing power supplies and boards that would be great. Eventually planning on making this a MultiWilliams with a JROK board and new control panel. Going to keep the defender artwork, found this sweet overlay at This Old Game,
http://www.thisoldgame.com/products/mult-williams-defender-version, which should work nicely. Still need to source some 4" wico leafs for robotron. I'll post some pics tonight.