Monstermug
Active member
Had a few moments to spare to fix a pcb which I got a few weeks ago from the king of mame pi's.
It was a dusty flying shark. Reported to have issues with lines through sprites. Switched it on and indeed it was just as described.
From experience I knew the roms 01 -> 04 were in charge of sprites. Ran them through my eprom to check and they all checked fine with mame.
Next were the six banks of 1024 x 4 static ram in the corner. First I probe them but they all seemed fine. Scoping the outputs showed the outermost ram had a weak signal on it's output.
With not much time to waste I decided to pull it out.
And installed a fresh ceramic dip (these banks of ram tend to get pretty hot!)
It wasn't easy pulling this chip out and the old chip fell apart as I removed it.
Plugged it in and viola! Sprites issued solved.
As it was a bit dusty I decided to give it a quick wash down.
Nice and new flying shark pcb ready to be returned to it's owner.
Love it when it all just goes to plan.
It was a dusty flying shark. Reported to have issues with lines through sprites. Switched it on and indeed it was just as described.
From experience I knew the roms 01 -> 04 were in charge of sprites. Ran them through my eprom to check and they all checked fine with mame.
Next were the six banks of 1024 x 4 static ram in the corner. First I probe them but they all seemed fine. Scoping the outputs showed the outermost ram had a weak signal on it's output.
With not much time to waste I decided to pull it out.
And installed a fresh ceramic dip (these banks of ram tend to get pretty hot!)
It wasn't easy pulling this chip out and the old chip fell apart as I removed it.
Plugged it in and viola! Sprites issued solved.
As it was a bit dusty I decided to give it a quick wash down.
Nice and new flying shark pcb ready to be returned to it's owner.
Love it when it all just goes to plan.
