Sinistar Help Needed

[YellowDog]

If you feel like learning more than most people care to, you can go out to the following link: http://arcarc.xmission.com/PDF_Arca...Recap_Stargate_&_Robotron_Troubleshooting.pdf

This is a fairly detailed walkthrough of probing for issues on a Williams board using a logic probe. Combined with the schematics, it will help you to locate potential problems. It is not a panacea, many of the chips will show as failing because of upstream/downstream chips that have failed, but it is a good start if you have never tried to debug a Williams board.

Or you could just send it off to be fixed. Several of us here rebuild Williams boards at reasonable rates.

ken

 

[72Demon]

OK, I think that may be beyond my skills at the moment. I do not have a oscilloscope. Any suggestions on who does repairs for the Williams boards????


Thank you everyone for all the help. Glad I got it narrowed down. Also, I was able to play Sinistar by using my Joust's CDU board! Really brought back memories from my childhood.

 

[Muel]

Well, since you've narrowed it down to a bad REV D Sinistar CPU (MPU) board, I would next try swapping out the actual CPU with the working one in the Joust CPU board. If your Joust still works with the Sinistar CPU, you've got a good CPU.

Then, do the same thing with the Decoder 6 and the Decoder 4 Proms - swap those as well.

If your Joust is still working, (with the Sinistar board's decoders) then your Decoders are good as well.

It's a poor man's way of debugging, but it has been known to work.

I'm glad to see that you're making progress!

 

[72Demon]

I was able to swap out the cpu, Decoder 6, and Decoder 4 all one at a time. And there was no difference in the Sinistar game using the cpu, and decoders from the Joust. I am guessing it is the CPU board that is the problem. Any recommendations on who repairs Williams CPU boards or any one selling a working CPU board?

 

[MajorHavoc]

Any recommendations on who repairs Williams CPU boards or any one selling a working CPU board?

Here is a hint: YellowDog said "Several of us here rebuild Williams boards at reasonable rates."

 

[72Demon]

I got the hint. PM sent to Yellowdog.