(Arcade Jamma PCB) - Sprites displaying Weird

[Edge-`]

Hello All, I thought this would probably be the best place for this type of question. I know Mal and a handful of other members here have some experience with Arcade hardware and maybe could suggest some answers to the issue.

Two years ago I bought a Black Tiger standup Arcade game/cabint (it looks quite strange as it is in an old Zaxxon cabinet ). The game worked fine and brought in an average amount of quarters. Yesterday I was doing spring maintenance (the Power Supply had decided that it no longer wanted to give out +5V on the correct wire so it wasn't properly powering the Jamma PCB) and after correcting the problem I noticed that now the game's sprites show like ghosts. The sprite graphice is drawn every 4 rows of pixels and then it is not ever 4 rows of pixels making it a bit hard to see the sprite.

It was starting to do this some time ago but eventually corrected itself somehow so I really thought nothing of it. Now it seems to be perm. I've tried reseating some of the chips on the PCB that were starting to come up to no avail. Is it possible I'm out of luck, or would anyone have any ideas on how to possibly fix this issue?

 

[Xavier]

how do you know that you getting the right volts/watts did you use a multimeter ? I notice in some games that they like different amps , dunno if it makes a difference though .

I always like to clean the harness out and clean the pins .

Are you video connections tight ?

 

[mal]

The only thing I can think of is to put the board into service mode (assuming it has one) and running it's self test (again assuming it has one).

It sounds to me like it may be either a bad rom or ram. I'm not an expert though...

 

[kahuna]

Originally posted by mal@Apr 18, 2004 @ 09:53 PM

The only thing I can think of is to put the board into service mode (assuming it has one) and running it's self test (again assuming it has one).

It sounds to me like it may be either a bad rom or ram. I'm not an expert though...

:agree

It could be bad RAM or a bad ROM, or one of the roms could have been knocked loose or vibrated partially out of it's socket.

Check for good connections and properly seated ICs first.