nesdev.org

Ok so I have a Yoshi's island that has garbled graphics and I kind of want to fix it. If the main chip is bad then there is no fix I guess. I had suggestions that it may be the fx chip is bad. I have reflowed the fx and main chips and it yielded the same results.

The glitches are not constantly identical, sometimes the title screen is messed up, some times the Yoshi's will have black squares going across the faces in the intro. Sometimes the sky will be blocky. I had the save 1 spot appear to the left once lol.

Since Yoshi's island is a fx gsu-2 version w/save. I am pretty sure that is it. Not sure if doom has save but I wouldn't destroy doom regardless. I want to try swapping the chip onto a stunt racer as stunt racer would be used to make a starfox 2 anyhow so if it didn't take no loss, but stunt racer has a gsu-1.

From what I have read in previous threads it seems the only difference between gsu-1 and gsu-2 is the save, however the fx chips are clearly different sizes and just wondering if anyone thinks I would be wasting the time swapping the Yoshi's island mask rom to a stunt racer board.

AIUI, the functional difference between the GSU-1 (and Mario Chip) and the GSU-2 is supporting 1 MiB of ROM vs 2.

Bah, Just checked and the rom chips don't match up anyhow. I'll just sell it as defective and call it a day.

Before you let it go, try replacing the SRAM chip. The GSU works it's magic on that RAM and the result is then DMA'd to the PPU.