Recent content by davidmorom

I assume you already tried the basic cartridge edge connector cleaning, so a contact issue is discarded. Did the cart work fine before modification? If it worked, you at least know that the CLPDs are OK. The crosshatch is displayed when the BIOS doesn't detect a valid P ROM header. The menu is...

Providing the chip is not damaged, there are several possibilities: Continuity is fine, but there can be bridges between or under castellated holes. Sometimes they can be very hard to spot, use a microscope or magnifying lens, at least. Check there is no continuity between adjacent pads (some...

It is, but only if C3 is not soldered yet.

The CPLDs are like this:

I made a quick test with the default gamelist_asm and MAME and, as leonk said on the previous post, the renaming is as follows (I think the neogeo-menu build.bat should give the files already renamed, or the documentation be more clear about it): crom0 -> menu-c1.bin m1rom -> menu-m1.bin prom...

I think you have to rename the menu files and overwrite the original ones, then run the bat without the patchmenu parameter. I used the original vortex menu, so I'm not 100% sure, test it on MAME before flashing.

Hi @MaRC! You have to take the original 64MB (megabytes) SROM file, split it in half (two 32 megabytes file), discard the second one (it's full of 0xFF), an concatenate the first part with itself (srom = srom1 + srom1), so the first half and the second half of the resulting file are the same...

Sorry for the triple post, I can't attach more than 10 files per post.

Mission Complete!! After doing extensive testing during the weekend, I can confirm that the capacitor replacement completely fixed all the audio issues. I ran trough every game at least a couple of minutes (including Xeno Crisis and Hypernoid), played a lot of matches of Windjammers, Neo Turf...

If the connections between the ROMs, the CPLDs and the board edge are the same, they should be usable. Otherwise you will have to do some reverse engineering to figure out how the signals are connected, and modify the CPLDs code in consequence. Regarding the dumping and flashing, on Vortex repo...

To be honest, I just put two lentil shaped trough hole capacitors I had on my component box, that probably are older than me 😂. Next monday I will measure the value of the original capacitors, the multimeter I have at home can't measure less than 1nF. As long as it works, I'm not touching it...

If you still have some boards with this sound issue, would be nice if you can test it, just to confirm.

Finally, I got the audio issues resolved!! I still have to extensively test it, but I think I now have a 100% working cart. I tried a lot of things to fix the audio: Checked and rechecked soldering and continuity, specially on V ROM Remove the voltage regulators and power the cart boards...

Finally completed the mod today, and started to test it. Everything is totally perfect, except for the sound. It is fine about 99.9% of the time, but occasionally there are slightly distorted samples or notes. This is mostly noticeable on the music of the Metal Slug series, there are some notes...