Re: Cinematronics CPU board problem

Don't worry Bill, it's just interference from your magnetic personality. :)

D.

On Mon, Jan 19, 2009 at 11:52 AM, Matt Rossiter <matt@rossiters.com> wrote:

> Man, I feel your pain there. I have a couple of boards like that too.
>
> Sometimes you need to reverse the clock position to get alternate
> signatures as listed in the manual.
> Double-check the power-up circuit on Page 5 of 7
> Make sure the JMI jumper is set correctly, which I'm sure it is.
>
> You might have to scrap the signature analysis and start from the RESET
> line with an oscilloscope and work back that way.
>
> Other than that - hopefully some of the experts on this list can advise you
> because I could use a little help as well. :)
>
> Matt
>
>
>
> On Sun, 18 Jan 2009 22:37:38 -0500, "William Boucher" <boucher@mnsi.net>
> wrote:
>
> Has anyone ever been doing Cine CPU troubleshooting using an exorciser
> setup and found 100% of the signatures to be correct but the board still
> won't run? I'm having this problem with a Rip Off CCPU. It is not a mod'ed
> board (meaning it uses 2716 eprom's). I've tested or replaced about 30
> chips including the eproms, a few bipolar d_roms, some 74LS163 counters that
> were messed up, a few gates, all the 74LS377's, the 74LS181's, the ram
> chips, all of the original chip sockets, and so on. Like I said, all the
> sigs are perfect. I tried the "load loop timer" test, the "spac" test, the
> "no-op" test, and the standard test. I've done them all 3x or more. The
> old original docs are loaded with numerical errors but I have sorted them
> all out already. The PCB is very clean, no open traces that I can find, no
> missing pads, no broken resistors or caps, etc. It is visually perfect.
> All the clock signals are perfect as well.
>
> I had a stack of about 10 old CCPU's and I finally decided to repair them
> all. I whipped through the batch and fixed 6 of them within a couple of
> days. I'm now down to just 3 left. I probably should move on to the last 2
> boards and come back to this one last, but I don't want to let it beat me.
> I'll keep at it even if I have to replace every last chip on the whole board
> one at a time if that's what it takes. At this point, I'm simply out of
> ideas.
>
> One of my other boards that doesn't work also has all good signatures as
> well. I can only hope that it doesn't turn out to be the same nightmare all
> over again. I don't really understand how all of the signatures can be
> correct and the roms all verified and the ram replaced with known-good chips
> and the thing still won't run.
>
> Any thoughts or suggestions?
>
>
> William Boucher
> http://www.biltronix.com/arcade_01.html
>
>
>
>
>

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Received on Mon Jan 19 12:45:47 2009