A
- Thread starter rewrite
- Start date
@caius ! That almost entirely fixed it!
Now I'm going to test all the graphics roms against the MAME set and see if they're good.
From there, I'm not wholly sure where to go, but it'll keep me busy for a little while anyhow, haha.
Thank you for all for solving the mysterious missing BD03. Extra thanks to Caius for providing me with the proper file to write!
Now I'm going to test all the graphics roms against the MAME set and see if they're good.
From there, I'm not wholly sure where to go, but it'll keep me busy for a little while anyhow, haha.
Thank you for all for solving the mysterious missing BD03. Extra thanks to Caius for providing me with the proper file to write!
Attachments
My ChipMax 2 doesn't read 82S129, or the c8751h-88 apparently. So aside from those I have checked everything and they verify against MAME just fine.
Time to explore a bit with the magnifying lamp.
Time to explore a bit with the magnifying lamp.
So I fixed a few cold solder joints, put all the ROMs back in, and noticed two traces cut:
https://imgur.com/L5QrKq1
Fixed that, and now my game is a mess...
https://imgur.com/eYhDJwX
I even tried removing the wires I used to fix the broken traces, and the issue persists..
It was better before I touched it T_T.
Might be time to call it a night.
https://imgur.com/L5QrKq1
Fixed that, and now my game is a mess...
https://imgur.com/eYhDJwX
I even tried removing the wires I used to fix the broken traces, and the issue persists..
It was better before I touched it T_T.
Might be time to call it a night.
A
Apocalypse
Maybe the severed traces were a factory fix. They seem drilled rather than scratched.
2 options:
- restoring the unwanted connections fried something
- you separated the 2 boards and didn't reassemble them properly
To me the bug on the sprites (horizontal jailbars or "invisible" lines) looks like a counter issue not data bits stuck (this would cause vertical jailbars). IIRC there's few LS161s in the sprite section.
Maybe Caius can confirm it.
Last edited by a moderator:
Frying something is what I'm afraid of having done...
Reassembling them improperly isn't very possible. It's just two ribbon connectors, and you can't mis-mate them. I definitely broke it... Wish I'd considered their possibly being factory prior to "fixing" them.
The ribbon cables could be bad. They get brittle with age.
It was working just half an hour before though, you know? I mean, I can test each pin on both boards I guess just in case. Would be better than my having fried something!
Yes, the severed traces are clearly a factory fix, you can understand it by how they have bee severed, they have been not accidentally cut but intentionally.So, please, restore all the fixes as found before (including wires)
Regarding the sprites bug, I'm agree with Apocalypse.Usually this kind of faults are caused by bad counters so check if around the sprites ROMs there are some of them (74LS161 are often used).Best would be to figure out all the relevant circuitry tracing the data lines of the ROM back.
Last edited:
Great.I'm going to add this GAL replacement for BPROM to our archive on JAMMArcade.
Sure, let me know and have a good trip!Thanks a lot.I'll let you know the result in a month when I'm back.
P.S.
Out of curiosity, which the board where these two PAL I converted are from?
Last edited:
Well they weren't too clear! They look like two tiny gouges, and since the boards sit back to back, it seemed plausible that someone had knocked them together rather hard, the board looks rough enough anyway.
The only thing I did was jump those two traces with a piece of wire, so hopefully it didn't affect *too* many things. I'll follow the traces and find all the things it may or may not have affected and replace them. Probably going to take a while though, heh. Once I solve that mess I'll poke around for the counters. Thank you both for your insight, and I'll chalk this up as a learning experience.
I was so excited that I was making progress that I just kept going. "Oh man, now it's mostly working with the new BD03", "Oh, there are a few cold solder joints on this board, let's fix those", "Oh hey, there's two little gouges in the PCB, maybe that's the problem, let's fix it".... And I broke it.
It'll get fixed though, I'm committed. And when it's fixed, I will hang it on the wall as my first PCB repair. I've fixed a lot of monitor chassis over the year, but avoided learning anything about game PCB's, so this is still a learning experience.
Anyhow, thank you both for your insight! I'll see what I can get done, will have to order some things and wait a while, I'm sure.
From what I can tell after half an hour of following traces and confirming with a multimeter, these are the IC's that were affected.
6L - HD74LS157P
6J - HD74LS04P
2F - HD74LS273P
6L - HD74LS157P
6J - HD74LS04P
2F - HD74LS273P
