Hi everybody,
I just bought a Combatribes PCB on eBay. It was - of course - faulty. The symptoms? The screen was inverted and it was in test mode all the time. Plus the button 1 and button 2 for each player didn't work.
The fault with the screen was of course the dip-switches. They connected to IC52 - one quick change of the 74LS253 responsible and the screen came back to normal.
The fire buttons not working was IC30, also a 74LS253. Change them out and all is well with the world.
One working PCB.
Hurrah!
I've put my own partial schematic which I was working on to diagnose the problem here:
http://www.mutant-caterpillar.co.uk/ian_stuff/Combatribes_sch.jpg
It's nowhere near complete but it may help other people to work out what's up if they have a problem with inputs too. I figured it's better than nothing so may as well share.
I just bought a Combatribes PCB on eBay. It was - of course - faulty. The symptoms? The screen was inverted and it was in test mode all the time. Plus the button 1 and button 2 for each player didn't work.
The fault with the screen was of course the dip-switches. They connected to IC52 - one quick change of the 74LS253 responsible and the screen came back to normal.
The fire buttons not working was IC30, also a 74LS253. Change them out and all is well with the world.
One working PCB.
Hurrah!
I've put my own partial schematic which I was working on to diagnose the problem here:
http://www.mutant-caterpillar.co.uk/ian_stuff/Combatribes_sch.jpg
It's nowhere near complete but it may help other people to work out what's up if they have a problem with inputs too. I figured it's better than nothing so may as well share.