TECH: Midway SI troubleshooting

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The boards that came with this cocktail version seem pretty much dead.
Power-up reveals no activity whatsoever, but it doesn't blow any fuses
or anything.

I swapped in my spare Sea Wolf set and got a screen-full of garbage,
which I expected, as that's what it does in my spare Sea Wolf

I swapped the Sea Wolf daughterboard for my Amazing Maze daughterboard
and the Sea Wolf boots into the attract mode fine. This allows me to
rule out a monitor, tilt switch or power supply issue.

With that bit of success, I tried the obvious next steps, first
plugging the Amazing Maze daughterboard into the SI motherboard. Still
dead, no output at all.

Popped the SI daughterboard into the known-good Sea Wolf motherboard -
garbage screen. So it appears that the SI daughterboard is bad in the
same way the Sea Wolf daughterboard is bad.

Anyone have any thoughts on what would cause this garbage screen
behavior on both daughterboards with a known-good motherboard?

Thanks!

Dave

 

[Guest]

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bad ram
John

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Hmmm, thanks for the reply John, but I don't see how that's possible.
This is the known-good motherboard, and if I swap the Amazing Maze
daughterboard back to it, it reboots Sea Wolf just fine. As far as I
know, there's no RAM on the daughterboard; it's all on the motherboard,
which in this case works correctly, albeit with the wrong daughterboard
attached.

Something's up with those 2 daughterboards...

Now, could definitely be RAM on the dead motherboard, that's for sure.
Found a post suggesting to replace the 10uf cap for a "no video" issue.
I'll be trying that today first...

Dave

 

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Archived from groups: rec.games.video.arcade.collecting (More info?)

I didn't necessarily make that assumption. I did make the assumption
that if the Sea Wolf motherboard boots correctly with the Amazing Maze
daughterboard attached, that it should do so with its own Sea Wolf
daughterboard attached, unless some problem on the Sea Wolf
daughterboard prevents that. I was mainly commenting on John's thought
about it being a RAM issue, which I can't see if the Sea Wolf
motherboard boots normally with ANY daughterboard at all, which it
does. The fact that the Sea Wolf motherboard fails to boot in exactly
the same way with both the SI and SW daughterboards I find
interesting...

I am more than sure I could be proven wrong however

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

> Something's up with those 2 daughterboards...

Not necessarily. You appear to have made an assumption
that any Midway "L" style daughterboard will boot with any
Midway "L" style motherboard, which is not true.

Alex
----
ayeckley@elektronforge.com
www.elektronforge.com