Centipede No shot.

drewscruis

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I swear I had a set of schematics for this but oh well (I ordered a new set since I hate online ones). Looking for where to start on this board. did the basic's reseated/cleaned the socketed chips. verified the roms (all good) put it in test mode (no beeps). basically it's making the shot but it doesn't show up on the screen. you can see it make a hit though.
 
I just replaced a transistor on my neckboard (different machine) that brought back the red on my machine.
 
the red is there on the opening screen. Ill have to look closer to see if the eyes in the centipede are there. also this problem follows the board tried in my test rig and an actual centipede.

here is what it was listed as wrong from the person i picked it up from.

Game plays, but the bullet/shot is missing also misisng eye and outline on the archer.
 
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yes, not necessarily specific colors missing but whatever colors that are the same as the current bullet color. had this a couple times. unfortunately i haven't looked at a centipede in quite a while and I know longer have much of that section committed to memory, though there are only a few things that should cause this in the video drawing circuits.

I'm certain I have a few examples on my centipede repair page
http://www.arcade-cabinets.com/resources.shtml

give it a look and see if any of those help you. it's possible the missing shots/missing/eyes/missing sprite colors are written up on the millipede page (or both) don't recall, but I"ve seen that a couple times. I'm trying hard to remember /isolate it down to a few components to check but my memory is failing me at this time. sorry
 
yes, not necessarily specific colors missing but whatever colors that are the same as the current bullet color. had this a couple times. unfortunately i haven't looked at a centipede in quite a while and I know longer have much of that section committed to memory, though there are only a few things that should cause this in the video drawing circuits.

I'm certain I have a few examples on my centipede repair page
http://www.arcade-cabinets.com/resources.shtml

give it a look and see if any of those help you. it's possible the missing shots/missing/eyes/missing sprite colors are written up on the millipede page (or both) don't recall, but I"ve seen that a couple times. I'm trying hard to remember /isolate it down to a few components to check but my memory is failing me at this time. sorry

IIRC, the bullets are sprites like anything else... there's not specific bullet generating circuit like on galaxian.
 
Going out on a limb here, but as centipede has two bit planes I bet they are separated across two Roms instead of stored linearly. Make sure all graphics Roms are seated and in good shape. Missing one bit plane would make some colors go away, some turn wrong, and some stay correct. Two bit planes combine to form four colors.
 
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