Model 1 Starwars Arcade Black Bar Void of Polygons

[TobyRieper]

Hi guys, have got a sega model 1 with star wars arcade. Its an odd one indeed, there is a black bar or or strip across the screen where alot of 3d graphics are missing/ corrupted. This does not effect background static images. The bar void of polygons is always present.

Is there anything inparticular i should pay attention too? I have done a reflow of the large surface mount ICs. Reset backup ram, reseated rom chips. I did a memory check and all the ICs are good.

Hope somone can help.

 

[andynumbers]

Steal a working video board from another model 1 game. Probably the 5422 chip.

 

[TobyRieper]

Thanks, I will pay special attention to this chip. Will check all the traces first. Failing that, another videoboard..shame i was hoping it would be a ram chip or something.

 

[andynumbers]

Check if it's a 5422 or 5422A. Most boards except for Virtua Racing should be running the A. This is a revised chip that doesn't fail as often. If it's the original 5422 just trash the video board. It's a ticking time bomb and they all fail. Nothing to do with the external traces. The chip fails internally.