CPS2 sparkles/artifacts

modessitt

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Phoenixed a Dungeons & Dragons: Shadow Over Mystara and am having some sparkles throughout most of the screens. See the short video below:



I cracked the A board and cleaned all the dust out. Don't see any issues with corrosion on any chips. A lot of this is surface-mount. Is there any hope for me?
 
The sparkles seems to be in a pattern.

When you dusted the pcb was it dust and grime or just dust?
How did you clean it, With air or liquid?

I assume you already reseated any socketed ic chips.

Sometime grime type dust get trap close enough to the smt legs and shorts out the pins next to the other pins.

By the patterns it is producing, I am thinking video ram.

This is where a good micro scope or jewels loop comes in handy. Some smt chips legs might pop loose due to not a lack of enough solder paste.

Ideally if you have the equipment you can remove the part add more solder paste put it back on.

Sometime you can reflow the solder to the pin But you need three hands. One hand to hold something metal as a heat sink on top of the ic chip leg.
 
The B board had a little corrosion on the two surface-mount chips next to where the battery was. I cleaned it off with a wire brush.

The A board just looked to be coated in dust. I used a dry paintbrush to clean it off.

I haven't pulled and cleaned ALL the socketed chips on the B board yet, and none (if any are there) on the A board.

Unfortunately the Video RAM is surface-mount and I don't have the tools to remove them. ..
 
Looks kinda like the boards are not connecting (pairing up) well.

What happens when you re-seat the "A&B" board? Or,

What happens when you try the "B" board with a different "A" board?
 
Looks kinda like the boards are not connecting (pairing up) well.

What happens when you re-seat the "A&B" board? Or,

What happens when you try the "B" board with a different "A" board?


+1 Do you have another board set to try testing/swapping with?
 
had a similar problem with my ssf2 turbo and when i pulled the a+b boards apart i noticed a bent pin that wasn't conecting when i put them together. Good Luck
 
I have some CPS 1 stuff like Magic Sword, Punisher, and Warriors of Fate, but that's it.

I'll ask, but I doubt anyone I know has a CPS2...
 
Did some more cleaning, but some sparkles remain.

But I have another issue - there are no characters on the screen - either the players or the enemies (no sprites?). I hear sounds like hitting and grunts. Buttons make noises like punching or hitting. Life meter goes down.

Character PROM? There were 2 ROMs not "phoenixed" but I figured they were sound as they weren't included in the "decrypted" zip file. Anyone know which PROM? Or some other culprit?
 
Heu Mod, stupid question. Did you check the +5? Too high or too low that will happen.
 
Take the cart board apart... find the electrolytic cap next the the removed battery. Short the leads together with a screwdriver and count to 5. Put it back together, power it up, and report back.
 
Take the cart board apart... find the electrolytic cap next the the removed battery. Short the leads together with a screwdriver and count to 5. Put it back together, power it up, and report back.

I did that after I redid the ROMs. Should I again?
 
I've checked CPS2 boards on Computer grade PSUs before, and they worked fine. So, an AT or ATX PSU shouldn't cause a CPS2 board to mess up like that. The board will pull the amount of power that it needs from the PSU, which is right around +5V. You just can't adjust it.


What you need to do is check the basics: Try the game with a different "A" board. And, if that doesn't work, then you need to burn a new set of revive roms.
 
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I've checked CPS2 boards on Computer grade PSUs before, and they worked fine. So, an AT or ATX PSU shouldn't cause a CPS2 board to mess up like that. The board will pull the amount of power that it needs from the PSU, which is right around +5V. You just can't adjust it.


What you need to do is check the basics: Try the game with a different "A" board. And, if that doesn't work, then you need to burn a new set of revive roms.

In my experience ATX supplies always run on the low side of tolerances. Arcade hardware isn't put together like computers are (internal regulation and what not) so they dont "know" that they are supposed to ask for more juice from the supply. It just is what it is.

I know its a long shot (and stupid considering who started this thread) but when I'm talking some one through a repair I always tell them to go to the dumb stuff first. ie, make sure the game is plugged in! :)
 
I brought the boards home to test on the bench, and will look for another source for the decrypted ROMs to compare to just in case the ones I got initially aren't good...
 
Well, those are program ROMs so unless they are teling the gfx ROMs to toss up those sprites I wouldn't think they were bad. Plus I would imagine that they would fail CRC checks upon power up (or during power up) so its kinda unlikely.

No change at home I guess?
 
What do you see on the screen when you power it up? Do the power on self tests pass?

Next, is this the original game on the board? If not, check the jumpers on the cart board to see if they are correct. Also, check the PALs to see if they are the correct ones.
 
Haven't tested yet. At the shop, half the time it would boot to the green screen even though I pulled both boards out of the case and made sure they were sandwiched tight...
 
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