Got some problem with a System16 Shinobi board some time ago, I thought it might be a good idea to share the way I fixed it ... it's not a hardcore repair log like Womble or others do, it's more like a "common sense" fix
It was also my first repair
So the title screen got "SEGA", "press start" and "freeplay" markings garbled
Strangely enough, parts of the attract mode were ok ...
... while other parts where garbled
On the last pic, the start of the sequence is perfect, but degrades gradually as the scrolling goes ...
I ran the self test, all the roms where good, so the problem comes from elsewhere.
Using Mame sourcecode, I ran through the documentation for this game, and started to remove some roms from their sockets in order to isolate the problem. After running the self test again, all the roms were still good (even those that were removed
)So from now on I didn't trust the self test for this board anymore
Luckily enough, I had a second Golden Axe board handy, so I swapped all the roms between the boards. Guess what ? The problem was still there.
So I swapped the PLA (programmable logic array) from the known good board, and everything was back to normal
It's the red circled IC in the next pic
Before ordering a replacement part on internet, I cleaned the pins using surgical spirit, and used thin sandpaper to remove oxidation ... and voilà ! The board is as good as new
I hope it wasn't too hard to understand, as I'm not used to do technical posts in english, and remarks are welcome
