Asteriods Deluxe from hell fixed

> Hi All,
>
> I appreciate your input and help. I finally got it!!!
>
> This was the asteriods deluxe board from hell....
>
> I can't complain to much because I got it for free, but this thing was
> wasted.
>
> Since I love a challange here is the story on the repair.
>
> 1. Got the board from an op for free
> 2. Took home and visually inspected.
>
> 3. All vecter ram was missing with hurt traces and bad desolder job.
> 4. 12.096 crystal was missing.
> 5. high score ram was missing with the same bad job as the vecter ram.
>
> 6. Replaced all ram with sockets and checked every pin with ohm meter for
> contact. Replace cyrstal.
>
> 7. plug it in and no picture just 2 short 1 long beep.
>
> 8. Ask for help on here.
>
> 9. Directed to the Asteriods encyclopedia.
>
> 10. Beeps is bad vector ram...HMMMM
>
> 11. Recheck all ram connections and find one I missed. Soldier jumper.
>
> 12. retry in cabinet. Now we can play blind, still no picture but its at
> least doing something.
>
> 13. Feel 74ls191 counter chips getting hotter then Hell...Yipes
>
> 14. Replace all 191's on the x axis.
>
> 15. try again... No picture.
>
> 16. find all the 157's that are connected to the 191's are baked too..
> Replace those..... No picture......find 374 that was connected to 191's
> baked...Replace.
>
> 17. Try again.... Finally a picture!!!!! yeah....
>
> 18. Notice bright dot with line off to the right top in attract mode
only???
> Strange
>
> 19. Check.....check... ask the group....check...
>
> 20. find 74ls109 not giving the halt output but it is giving the /halt...
> hmmmm replace.
>
> 21. Test... Still same thing... check output of 109 still held low...oh
> no... unplug. replace 74ls174 that halt pin goes to....
>
> 22. Try again..... YEAH it finally works.....
>
> 23. Notice when all dip switches are off that in attract mode it is
slightly
> glitchy with lines comming off some rocks and once in awhile some random
> stuff on screen...???
>
> 24. Game play and everything else is fine with no glitches??
>
> 25. Set dipswitches a different way and the glitches go away in demo
> screen??? Not sure what is up with that anybody know?? If this the vector
> rom to slow problem?
>
> Thanks all
>
> For your help.
>
> Fred
> Juice28

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Received on Sat Jun 29 15:47:29 2002