Sunset Riders sprite problem

yavuzg

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hey guys,

Asking your opinion about this glitch...

IMG_2301_zpsiyxfssyw.jpg


Sprites are shifted quarter screen right and dissapear on the left 3/4 of the screen area. When they are beyond the visible right screen then some bars appear (as seen on the pic).

Some more pics...

IMG_2300_zpsjqdnzndg.jpg


IMG_2297_zps7keljrdd.jpg


And the mask rom test...

IMG_2295_zpsprf1t0i5.jpg


Things I've done:

1) Searched for gauged traces. None found so far.
2) Desoldered the mask rom 3L and checked with romident. It is OK.
3) Reflowed the sprite generator ASICs (053244 and 053245)
4) Checked the bus controller 245s (8J and 8K)

Anybody seen similar behavior?

I'm leaning towards the fact that 053244 (and/or 053245) ASIC might have gone bad...

What do you think?

Edit: Forgot to tell, after you die, when game asks for more credit (please continue screen) when coin up and continue, all the sprites completely dissapear. I don't know what it means but just wanted to mention this...
 
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Those Mask Roms are notorious for failing. Im shocked it actually checked out. Did you socket it? I would burn a new one and throw it in just to rule that out for sure.
 
the rom chip can be good but the traces can be shorted or broken causing the game to report it as bad, give the board a good eyeball test and then check it with a logic probe to see if anything is stuck high or low
 
I'm also surprised about the mask ROM... I fixed one a while back that said bad mask ROM, and it was actually a bad ROM.

DogP
 
It could still be the mask rom

I had one on a Final Fight that read ok on my reader rom id OK but didn't work on the PCB at all once i replaced that rom with a new one had no more issues at all. I guess it might of been on its way out maybe? could never figure out why in the end

Have you also check the sprite ram?
 
Those Mask Roms are notorious for failing. Im shocked it actually checked out. Did you socket it? I would burn a new one and throw it in just to rule that out for sure.

I never socket mask roms if they check out OK due to aesthetic reasons :) Will reconsider it if everything fails though...

the rom chip can be good but the traces can be shorted or broken causing the game to report it as bad, give the board a good eyeball test and then check it with a logic probe to see if anything is stuck high or low

I agree. I've examined the area with a 20x magnifier as best as I could but you never know. I've checked all the pins with oscilloscope during mask rom test and during game play. There were activity on all address and data lines. So I guess this rules out the gauged trace possibility between ASIC and ROM.

However, I found A3 line of the 3L ROM stays high when everything is idle (i.e. where there are no sprites on screen such as some demo screens and test screen) but I see activity when sprites appear (or I run mask rom test). I gently lifted the specific pin of the ASIC (Konami 053245) which is directly connected to that address line and run the board without that connection, the sprites issues were still there but with distorted sprites. So I guess that may not be the real cause of the issue but may be one of the s**t in the pile of s**t inside the ASIC :)

I'm also surprised about the mask ROM... I fixed one a while back that said bad mask ROM, and it was actually a bad ROM.

DogP

I wish I was lucky too :)

It could still be the mask rom

I had one on a Final Fight that read ok on my reader rom id OK but didn't work on the PCB at all once i replaced that rom with a new one had no more issues at all. I guess it might of been on its way out maybe? could never figure out why in the end

Have you also check the sprite ram?

I've checked them with oscilloscope in circuit (but that is just a bus check not individual ram check). I also piggybacked them but no change. I may try to desolder them and check them seperately though...
 
have you tested the rom sockets to make sure that what is going to the legs of the chip is actually getting to the board. I mean to say check continuity from chip leg to board itself and see if the socket is working correctly
 
Update...

I've replaced the 053244 and 053245 one by one. Snatched the replacements from another Konami PCB (Premier Soccer) which was 100% working.

Result? Nothing changed...

However, when replacing 053245, I noticed one rusted via underneath the IC.

IMG_2451_zpsl3g1nnls.jpg


Followed and tested it which turned out to be disconnected due to corrosion. Apparently this via was on the line which connects pin 25 of 053245 to pin 18 of 053244. I know, these two guys works together and guessing this connection is part of the communication bus between them...

Anyway, that fixed the problem...
 
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