MV-1C / NeoSD MVS / No ADPCM

Roamin64

Timid Neo Newbie
Joined
Apr 22, 2021
Posts
3
I bought a MV-1C from ebay that's been giving me headaches since day 1. First, it had a calendar error and I eventually had to change the NEC RTC. Then days after I got a work ram issue. I ended up changing 2 RAMs , and it's back into working. I thought my issues were done. Played a bunch of games with my NeoSD, all seemed fine (I don't have the biggest experience with neo geo games). Until I tried metal slug 4 and 5. First , there were lines across the entire game, there is no ADPCM music , only sound effects. I ended up reflowing a few pins on the NEO-GRZ (somewhere around pins 185-190). Then , the sound was gone! I then decided to reflow pins on the NEO-YSA2 chip, from pins 73 to pins 113 or so. Sound came back.

The one issue I can't grasp is the missing ADPCM music from all the popular titles. Metal slug 4 and 5 , pulstar, blazing star, Rage of the dragons. They are all missing ADPCM.

Unless NeoSD doesn't support ADPCM music ? I have not read anywhere anything about this. The closest I found was modifying multicarts with capacitors to gain ADPCM back. Does the NeoSD require any mods for ADPCM ? Since all the audio chip is embedded inside the NEO-YSA2, I'm thinking the yamaha 2610 bit the dust in the package.. As I've seen the NEO-YSA2 being faulty often, especially for player inputs.

I already ordered a new board thinking nothing could be done to this one, but I'm still willing to try a few things to get this back up.

I have a oscilloscope , logic probe (data only , no audio) , multimeter, solder rework stations..

Are there any source for the NEO-YSA2 except donor boards ? Thanks for any input!
 

lachlan

drunk downunder!, aka. Muff Diver.,
Joined
Feb 13, 2005
Posts
17,271
MS4/5 run perfectly fine with the NeoSD on both my AES consoles, they ran fine on the 1C and 1FS that I had previously also with the NeoSD so it's not the cart.

1C's are notorious for their integrated mega IC's where problems inside the IC's are impossible to repair. Considering it's been a problem board I'd hedge my bets on a better experience with a new 1C or any other problem free MVS board.
 
Joined
Dec 7, 2000
Posts
9,090
That's not normal. Does the MV-1C work right with real game carts? (If you aren't sure if ADPCM is missing or not, please post a video.) If it works with real carts, the NeoSD could be faulty.
 

Roamin64

Timid Neo Newbie
Joined
Apr 22, 2021
Posts
3
The NeoSD is the only cart that I have. Both cartridge connectors were completely changed and every single pin has been tested for continuity.. With the old and then with the new connector. Although I had tested them and there was continuity even to that pin that I needed to resolder on the NEO-GRZ to fix the vertical lines in the screen.. Pushing the pin to measure continuity must have been enough to give continuity during the test.. So it's possible although I've tested continuity that there is still a loose pin somewhere .. but by now I've reflowed most chips.. There is one other error, at least one game prompts a "MVS SLOT CHECK , Ver2.30 00/04/25, M1-ROM ERROR" after launching , Metal Slug 5, letting the game run on the title screen eventually ends up crashing the game , but at that point I can still return to the NeoSD menu with the button combination. Haven't played for hours though, maybe the game crashes somewhere during play also.. Turning the game back on this morning , the sound is gone again. When this happens , scoping the clock , L/R select and data lines, the data line doesn't move and stays at 0 volts. Both the clock and L/R select are scoping fine.

I really doubt it's the NeoSD.. Sadly I have nothing else I can test with , no carts, no access to another MVS until the next one arrives from China.. somewhere between May and July it says ..
 

HMG

H = Heinously, M = Massive, G = Gonad,
Joined
Apr 3, 2011
Posts
4,881
Buy a cheap, real MVS cart to test with
 

Roamin64

Timid Neo Newbie
Joined
Apr 22, 2021
Posts
3
Mmmm, so it seems there still are some bad contacts.. Moving the cart around the sound comes and goes, and so does that M1-ROM error. But even when the M1-ROM error isn't present , there still is no music..
 

J69

Hardened Shock Trooper
Joined
Jan 22, 2006
Posts
428
I've got a NeoSD MVS cart that has suddenly
lost sound. I've got 2 MVS mobos and it works in neither. Sound works fine in the MVH1F test menu so it's not an issue with the mobo
 

lachlan

drunk downunder!, aka. Muff Diver.,
Joined
Feb 13, 2005
Posts
17,271
Mmmm, so it seems there still are some bad contacts.. Moving the cart around the sound comes and goes, and so does that M1-ROM error. But even when the M1-ROM error isn't present , there still is no music..
I had the same sort of issues when using an MVS-AES converter. I think it honestly comes down to poor contact being made because it would work on some insertions and not others (most..)

Metal Slug 3 for instance will throw up an M1 error but other games will just have no sound at all. Maybe the edge connector on the NeoSD isn't as great as we'd want... it sure doesn't look as good as a regular cart.
 

RAZO

Kyo's Flame
Joined
Dec 2, 2006
Posts
8,440
I've got a NeoSD MVS cart that has suddenly
lost sound. I've got 2 MVS mobos and it works in neither. Sound works fine in the MVH1F test menu so it's not an issue with the mobo
Try this. Take the Neosd pcbs out of the shell and insert them into the cartridge slot.
 
Top