Thunder Dragon 2 Graphics Glitch

[chomponooch]

I've Thunder Dragon 2 (NMK), physically it seems good, rom check OK, gameplay working correctly - but it has a weird graphics glitch - some of the background sprites are messed up.

pics https://postimg.cc/gallery/1iawrie70/

What would be causing this?

Thank you.

 

[Darksoft]

That is a problem with the background ROMS. It can be among others be caused by:
* Faulty Eproms/ROMS
* some logic device like 74LS broken
* a trace cut
etc.

 

[chomponooch]

OK - thank you - I'll check it.

 

[chomponooch]

Finally problem resolved - two Sony CXK58256 (RAM) chips have been replaced and now board works 100% OK.

Thank you.