Color issues on a Monster Maulers PCB

[quoth09]

http://s293.photobucket.com/albums/mm68/badebay/PCB%20Issues/Monster%20Maulers%20JP/

Images of what is going on can be seen at that link, which you can compare with the ones on it's KLOV entry, and easily tell it's not supposed to look like that.

The actual board is Kyukyoku Sentai Dadandarn, which is the JP version of the game, but the layout is the EXACT same as the US one.

I'm confused because one time I hook up the board, it has color inversions on some sprites, but not others, then the next time it will be on other objects/sprites.

It's doing stuff like making the fireballs off color/blue sometimes (they are supposed to be red), character sprites have inverted colors, etc.
The laser at the beginning from the ship after you insert a credit and hit start is supposed to be blue, it ends up being red or orange.
It does it randomly, which leads me to think it is a connection issue, but the problem with that is that I also have a Monster Maulers (US) board, and it is completely fine, no matter what.

I don't have access to a cab at the moment, only a supergun with a JROK encoder+sync cleaner, which everything else works fine on.


If you know anything about this board, then you know how uncommon it is, so I would definitely like to keep it if possible, otherwise I am going to have to return it to the distributor.

 

[ttooddddyy]

The colour phase is all screwed up but notice also that the girl on the right has no colours at all - so this is not a RGB video drive mix up issue. At first I was thinking a cracked resistor array in the RGB DAC ladder.
This looks more of a gfx issue effecting sprite rendering.

What happens if you tap around the boardset whilst its running. May be a bad connection.

 

[quoth09]

The colour phase is all screwed up but notice also that the girl on the right has no colours at all - so this is not a RGB video drive mix up issue. At first I was thinking a cracked resistor array in the RGB DAC ladder.
This looks more of a gfx issue effecting sprite rendering.

What happens if you tap around the boardset whilst its running. May be a bad connection.

Each hook up is random - sometimes graphics are completely black for sprites, sometimes not. Usually just messed up colors. The photos I took are from one of the worst hook ups I have had, so it's not like that all the time.

Nothing at all happens if you move it around while running. Stays the same.

Btw, board passes all color tests, and ROM/RAM all shows up as OK.

I'm going to try sandpapering the JAMMA area later today, to see if that will help with the connection, as it's already clean.

 

[madman]

Cleaning the JAMMA edge won't do anything, that only outputs 3 different color signals. If you had a problem there, the entire picture would be wonky, not just select sprites.

 

[quoth09]

Yeah, you were right, didn't even help in the slightest.

I have already contacted the distributor I got it from, they are getting this board back none the less, other wise they will be enjoying a nice chargeback from my credit card company. The only way that would be avoided is if it can be fixed, and I'm not going to trust them to it; they already fixed another board that came back defect in a different way.


Edit: I ended up keeping the board, and had channelmaniac fix it. Looks like a poor soldering job on one of the main CPU's at the Konami factory. Glad I kept this.

 

[channelmaniac]

Yup!

Ttooddyy had it right. GFX corruption was back at the chips that did the control/rendering.

I held the board in my hand and pushed firmly on each chip individually until I located the culprit. I resoldered surface mount IC 25V and tested the board.

Once it was resoldered, I could jostle the board like crazy and not have any effect on the colors. In other words, I gave it a hearty shake test.

RJ