Just got an untested Atari Xevious PCB and it's working but there are no background graphics.
The title is made of background graphics and is obviously not appearing properly:
Plus in demo mode the background is completely blank. The sprites and text are there but nothing else:
I was checking the LS174 at 3J and noticed that pins 11,13 and 14 were inactive.
I tracked where those signals came from (custom 13XX at 1J) and on removing it I lost three legs-typical namco customs.
I have a spare on an old part board so I tried that but it made no difference but when I pushed on the chip with the game running I suddenly got the backgrounds back.
It was a bad socket so I replaced that and managed to fix the busted legs on the original custom and got this:
Nearly there but as you can see on the edge of some of the graphics there is corruption.
This turned out to be a bent pin 1 on the prom (I think that's what it is anyway) at 4H.
Sorting that has restored all the graphics.
Jamma adaptor is only wired for left/right and one fire so need the add some more controls and see if the rest plays properly but the sound FX are present and correct so far.
The title is made of background graphics and is obviously not appearing properly:
Plus in demo mode the background is completely blank. The sprites and text are there but nothing else:
I was checking the LS174 at 3J and noticed that pins 11,13 and 14 were inactive.
I tracked where those signals came from (custom 13XX at 1J) and on removing it I lost three legs-typical namco customs.
I have a spare on an old part board so I tried that but it made no difference but when I pushed on the chip with the game running I suddenly got the backgrounds back.
It was a bad socket so I replaced that and managed to fix the busted legs on the original custom and got this:
Nearly there but as you can see on the edge of some of the graphics there is corruption.
This turned out to be a bent pin 1 on the prom (I think that's what it is anyway) at 4H.
Sorting that has restored all the graphics.
Jamma adaptor is only wired for left/right and one fire so need the add some more controls and see if the rest plays properly but the sound FX are present and correct so far.
