Need help figuring out an issue on a SF2:WW

So a friend and fellow forum member picked up a World Warrior (not bootleg) board a while back that 'mostly' seems to run fine with a curious issue: some of the sprites do this strobing/flashing thing rapidly, a bit like how games various capcom games would try to do transparency effects from the era (every other frame).

For example, The "Street Fighter" title text does this, Ryu's normal costume does this - if you go into the test menu, it happens on some colors and not others in the object/sprite test menu, like when set to "color 09" (for example, not exclusively) but not on all of them.

I had borrowed the board from him just on the off chance it might be an easy fix like an eprom having been corrupted, because at least one of the eprom windows was oncovered, and I have an eprom programmer. It wasn't that though, because the data on that ROM was intact.

Complicating the matter somewhat is that this revision (910228 USA) of the game is apparently one that uses two different PALs from other revisions (IOB2 and C632B).

Anyone have any suggestions where to start? Could a bad PAL be to blame for this kind of an issue?

Have you tried separating all the boards and reseating them? That helps sometimes.

shadowkn55 said:

Have you tried separating all the boards and reseating them? That helps sometimes.

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Did that, yeah. Thanks for trying! Also made sure all the mask roms/eproms were sell seated and not popping out (one was). The board's pretty clean, really.

The whole thing about being the variant with the funky pal means my previous idea of finding another WW board and trying just the B board from the 'broken' onewith the other A+C is muuuuch more of a pain to narrow it down. That's why I posted, hoping people would be able to say what 'kind' of failure would lead to this sort of behavior.

I just wanted to chime in and say that the problem board actually belongs to me. Fayk is helping me out with it since I don't have an eeprom burner and all. His help and everyone else's help in resolving this problem is appreciated.

I have found this place to be very helpful with WW boards. http://cps1repair-doujin.com

bustedstr8 said:

I have found this place to be very helpful with WW boards. http://cps1repair-doujin.com

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They're that bad, eh? What does PC Load Letter even mean?!

Sometimes if you lift a corner of the C board it will clear strobing stuff up. Just lift the back left corner about 1/8" and see if anything changes.

Xian Xi said:

Sometimes if you lift a corner of the C board it will clear strobing stuff up. Just lift the back left corner about 1/8" and see if anything changes.

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Sadly, I tried this (several times) and it didn't solve the issue.

I did (since I own a (different revision) WW board) try swapping the A board just since that was a small bit of data I could gather. No change.

I tried swapping C boards (complete with swapping the PAL as well to keep that the same) but oddly (?) couldn't get it to boot with the other C board. No idea why. Several attempts, but got it swapped back and worked fine. SO not much data gathered there.