TMNT

[Retroman839]

My turtles game now has an issue where the sprites just keep scrolling looping

Video here of the issue ..

Any help appreciated

Passes mask rom check

 

[TheDaddy]

Sneaky feeling it will be one of the customs , 90% of the time its that on konami boards.

They are my favourite board to work on (i hope you can read the sarcasm in that !)

Dave.

 

[Retroman839]

Sneaky feeling it will be one of the customs , 90% of the time its that on konami boards.

They are my favourite board to work on (i hope you can read the sarcasm in that !)

Dave.

Yeh I am following your Tmnt thread closely .. ❤️. 🤣🙌.
You know it .. I hope my board can be fixed though in all seriousness…

I just hope it can be -

 

[Retroman839]

Sneaky feeling it will be one of the customs , 90% of the time its that on konami boards.

They are my favourite board to work on (i hope you can read the sarcasm in that !)

Dave.

Yeh I am following your Tmnt thread closely .. ❤️. 🤣🙌.
You know it .. I hope my board can be fixed though in all seriousness…

just hope it can be -

I have pulled this from Arcade projects

This could be caused by a faulty mask rom, or any one of a million other logic ic's being faulty such as a mux or the static ram. Depending on the condition of the board, it could even be a broken trace / via as these Konami boards suffer quite badly from corrosion.

 

[TheDaddy]

Yeh you go down the line (or i do) in this order :-

1) check and verify rom
2) probe entire circuit ttl, ram , rom for floating pins.
3) check and verify ram
4) checkball ttl in circuit.

If all pass its the customs. Problem with yours is its passing the tests !!! Hence me saying large chance its customs.

As the article says no mater how good the condition of board you can get tracks that break. I had several on my Simpsons and one was broken under the custom (threw me for a while).

Dave.

 

[Retroman839]

Yeh you go down the line (or i do) in this order :-

1) check and verify rom
2) probe entire circuit ttl, ram , rom for floating pins.
3) check and verify ram
4) checkball ttl in circuit.

If all pass its the customs. Problem with yours is its passing the tests !!! Hence me saying large chance its customs.

As the article says no mater how good the condition of board you can get tracks that break. I had several on my Simpsons and one was broken under the custom (threw me for a while).

Dave.

Hiding under the chip!
Little basterd …
Hhhhmmmm. I missed a good desolder tool recently .. but I wouldn’t want to touch this one.. need to start on some less precious’s

 

[TheDaddy]

Yeh and konami boards are ( in my opinion ) hard to work on and a pain in the arse getting chips of.

If your just starting with solderjng / desoldering give me a shout i have shed loads of bootleg boards you can practice and fix or use for spares. All at the right price as i need to slim down !

Dave.

 

[Retroman839]

Yeh and konami boards are ( in my opinion ) hard to work on and a pain in the arse getting chips of.

If your just starting with solderjng / desoldering give me a shout i have shed loads of bootleg boards you can practice and fix or use for spares. All at the right price as i need to slim down !

Dave.

I thank you most sincerely but I do have a stack of such boards my self 🤣🤣🤣🍻. And it’s getting bigger
I just need a good desolder tool right now .. mist one right in my town as well because I been away..

But I have just spotted a Suspect trace .
Going to check it out now ..

 

[Ace`]

Bad RAM/ROM wouldn't cause that fault. Logic or custom, most likely custom surface mount ic.

 

[Alpha1]

@Monstermug fixed my one!

 

[TheDaddy]

@Monstermug fixed my one!

Yeh he is good at surface mount , i hate the damn things. I can do them but one slip or uneaven heat you bolloxed the whole thing up.

Dave.

 

[Retroman839]

Will have a word with monstormug then
👍… cheers .

Next up

 

[Retroman839]

Bad RAM/ROM wouldn't cause that fault. Logic or custom, most likely custom surface mount ic.

Has this custom been reproduced ?

 

[Ace`]

no you'd need a donor board.

 

[Retroman839]

no you'd need a donor board.

Only same game or poss other titles carry this same custom ? Turtle normal perhaps

 

[TheDaddy]

Only same game or poss other titles carry this same custom ? Turtle normal perhaps

Other titles as well , anything with the 4 chips on i think.

Dave.

 

[Retroman839]

Identifying the bad custom ..
I guess probe it ? Look for a stuck or floating singnal…

prob beyond me but I do have scope and probes

 

[TheDaddy]

Prety much but dont probe the chip as they are so close you will short the pins for sure, Find where they go and probe there. Have a look at the CPP and it will tell you what chip does what , Its what I would do as I always forget. 2 work in unison with each other, so its one of 2.

Dave.

 

[Retroman839]

Prety much but dont probe the chip as they are so close you will short the pins for sure, Find where they go and probe there. Have a look at the CPP and it will tell you what chip does what , Its what I would do as I always forget. 2 work in unison with each other, so its one of 2.

Dave.

CPP?

 

[TheDaddy]

I am out but if your seach for tmnt mame cpp it will show you the driver stuff and tells you loads in there.

Managed get it :-

mame/src/mame/konami/tmnt.cpp at master · mamedev/mame

MAME. Contribute to mamedev/mame development by creating an account on GitHub.

github.com

Dave.