Received this game for a repair.

The game had messed background images

Shorting some data pins rams I found the one responsible for the tiles arrangement.

I replaced the one marked in red below and it was infact faulty but it didn’t fix completely the problem.

I noticed that the 74ls745 above it was pressed down badly like if it was hit but something.

I decided to unsolder it and test the continuity of all the pads and infact I found three of them (marked in red) that visually were OK but they had no continuity

with the other chips.

That meant that the internal pad was broken so bad it detached internally

 

Making some ugly flying wiring with something I had at hand I tested the game which was fully restored