MV2F graphic glitches

[raulos]

Found this one in my arcade pcb stockpile. A lot of graphic issues - in fact just a fix layer seems to be good.
So, again i need some advice. Where to start?

 

[ack]

Its a common problem on 2 slot boards that a leaky battery causes graphic issues like you are seeing. There are a number of traces around the battery that carry the sprite data.

 

[raulos]

I cleaned battery residue, checked all traces from neo-zmc2 (specially those exposed ones) for continuity. All are good.

 

[ack]

I assume the issue is happening on both slots right?

NEO-257 - NeoGeo Development Wiki

wiki.neogeodev.org

NEO-ZMC2 - NeoGeo Development Wiki

wiki.neogeodev.org

NEO-B1 - NeoGeo Development Wiki

wiki.neogeodev.org

The NEO-257 act as a 2 to 1 multiplexer for the sprite data (CR0-CR31) coming from the both slots. The NEO-257 will pass along the active slots CR0-CR31 data to the NEO-ZMC2. So you will want to check all the CR0-CR31 outputs from the NEO-257 are making it to all the CR0-CR31 inputs on the NEO-ZMC2. The NEO-ZMC2 will do its business and send the data to the NEO-B1 as the GAD0-3 and GBD0-3 signals, so you will want to verify those as well.