I picked up a non working Dragon as my first solid state. It wouldn't be any fun if it worked right off the bat, would it??

I've been going through Clay's guide about systematic testing and start up. I installed correct fuses, tested all transformer outputs, tested bridge rectifiers, etc. Bottom board seems good. Power supply is a new Marco I believe from online search, former owner installed it hoping it would resurrect the beast. Outputs from that are good. 5V and 12V are good on the CPU board. Original battery was still on there but absolutely no evidence of leakage oddly enough, and I've removed it.

So right now at power up I get the 5s delay, then score displays come on all zeros, then after a few seconds it changes the displays to something that resembles a number 5 (I'll post the pic), then after a few seconds flashes back to the zeros, and repeats.

Something concerning is that when I power it up with the coin door connector disconnected it doesn't go to slam tilt mode. There was a wire soldered across one of the caps on the CPU that I see was to defeat the slam tilt but I have removed it and still get no slam tilt.

Can someone point me in the right direction? What is this display telling me?

IMG_20161030_203721848 (resized).jpg

Found it!

I noticed that each time I turned it on, although it showed zeros in the score windows, there was a number in the credit window. And finally I noticed that number was incrementing each time I power cycled it. So I shook down the coin door and found the wire actuator in one of the coin slots was bent and jammed into its leaf switch.

I removed that and now it boots and plays!

However, it still doesn't go into slam tilt if I open those switches just for kicks. I wonder if that circuit was burned out by the defeat? Oh well, I don't need it. Everything else seems to work. Time to clean it up.

Yes that's how this was when I got it. I removed that shunt but it still doesn't recognize if those switches are opened. Not that I need it to, I'm just wondering if that's indicative of a problem.