Donkey Kong Jr pcb (Mario Bros conversion) repair

I got this original Donkey Kong Jr pcb fairly cheap as it had been converted to Mario Bros and was in quite a state, it also didn't work. Since I already had a working original Mario Bros and my only DKJr was a bootleg board the plan was to convert it back to DKJr.

This is what it looked like when I got it, first thing I did was strip all the socketed chips and mod wires and clean both pcbs. Once it was clean(er) I was able to see all the cut traces and lifted pins much easier and start restoring it to stock.

After replacing all the eproms with the correct DKJr code and three colour proms I powered it up and was greeted with a screen of garbage. The cpu wasn't running, checking the Z80 and it was dead. I replaced it but no change, the fluke confirmed that I had bad ram (2114s). I replaced the rams at 3A and 3B this brought the game back to life.

It was mostly working but there were black lines and scrambled sprites. I found a 74LS283 @8R with floating output on the video (bottom) board, replacing this helped slightly but the image stayed mostly the same.

Another 74LS283 @8J failed in circuit tests, replacing this helped a lot but didn't quite fix it.

Almost fixed but there's a line through junior, and even more lines when going left or right.

I then found yet another bad 74LS283 @8P.

 All Fujitsu of course.

 Three sockets and three new 74LS283s.

 Colour changes in the screen shots is because of the camera not the board.

This fixed all the graphics issues, all that was left to do was remove all the components that had been added to add on board audio amplification since my jamma adapter does that and I didn't want it amplified twice.

Repair complete.