mikejmoffitt
Mickey's Coach
- Joined
- Feb 6, 2014
- Posts
- 578
I've had this MV-2 for a long time, and it had vertical lines and very corrupt looking flickering graphics. Just a few days ago, I got around to addressing the problem - the old battery corrosion had destroyed almost all of the traces coming down from NEO-ZMC2, which does pixel multiplexing. The graphics are now almost perfect. I also repaired one bad ADPCM-A address trace to fix sound.
I am left with only one problem. I've made sure my wiring from my repairs is correct and there are no shorts or egregiously long wires. The problem is that occasionally the edges of sprites will have flickering pixels that go between two states. This is most evident when H-shrinking is being applied but not always. I've tried to capture some evidence of it in a video:
http://csh.rit.edu/~moffitt/img/mslug2.mov
There are a few vias I can push on with my finger and make the dots change a little bit - something is definitely floating when it should be driven. The problem is I've followed the traces around and they are hard to follow as they go closer to the rest of the graphics chipset. I suspect the other end connects to ZMC2 but as they go under ZMC2 I can't really tell what is supposed to go where. If I can avoid de-soldering ZMC2 that would be great.
If anyone has any pointers I would appreciate it. I'm so close to having this as a fully working board.
I am left with only one problem. I've made sure my wiring from my repairs is correct and there are no shorts or egregiously long wires. The problem is that occasionally the edges of sprites will have flickering pixels that go between two states. This is most evident when H-shrinking is being applied but not always. I've tried to capture some evidence of it in a video:
http://csh.rit.edu/~moffitt/img/mslug2.mov
There are a few vias I can push on with my finger and make the dots change a little bit - something is definitely floating when it should be driven. The problem is I've followed the traces around and they are hard to follow as they go closer to the rest of the graphics chipset. I suspect the other end connects to ZMC2 but as they go under ZMC2 I can't really tell what is supposed to go where. If I can avoid de-soldering ZMC2 that would be great.
If anyone has any pointers I would appreciate it. I'm so close to having this as a fully working board.