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    Neo Diagnostics ROMs

    The bank error board is a lot closer to working since if it got that far, almost every other part tested OK. If you are completely sure that it's none of the traces on the page or my post, can you probe the NEO-D0 pin with any 1991+ game inserted and see if you get any pulsing? It should pulse...
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    Neo Diagnostics ROMs

    If the error details are the same every time, then it's probably a bad chip. The chip is marked "42356" on the board and should the one immediately to the left of the battery. It's the one with pin 11 connected to pin 5 of the 68k. I posted about this in another thread where another poster had...
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    MV1A Audio Issues

    That sounds like a YM2610<->cart slot connection issue since it's only affecting PCM playback. Most of the other channels are used for music instead of sound effects so parts of the music could work fine despite the distortion. I would check the SDRx (ADPCM-A) pins from the YM to the PROG slot...
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    Can ADPCM-A and ADPCM-B files be used with NEO-PCM

    I vaguely remember seeing a bootleg board with a PCM based game and it was implemented using just discrete logic. I think it was on this forum but I'm not sure what the game was. I don't know if there's an open implementation for the PCM publicly available but there are 2610 bus timings up on...
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    Can ADPCM-A and ADPCM-B files be used with NEO-PCM

    Blue's Journey looks interesting in that they left v21 empty on the original board. That makes it work with the PCM since the v22 wouldn't overlap with the v11 ROM. If it used v21 + v11 (like Puzzled does) then I expect you'd have the address overlap issue.
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    Can ADPCM-A and ADPCM-B files be used with NEO-PCM

    The sample addresses in the M1 ROM would need to be patched for one of the channel types. There isn't an easy automated way to do this. The pre-PCM boards have both channel types in their own separate address space while it's a single combined address space for NEO-PCM boards. If you tried this...
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    Bios Pinout for 1st Gen AES

    Bumping this since I wanted to add some info after repairing a NEO-AES that was also clicking due to BIOS reading issues. This is the thread that pops up first in search results so I think it's a good spot to post it. The required pins to make BIOS pin 20 pulse originate from these so this...
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    MVS Z80 error

    Are you completely sure the G0 swap caused the the resets and cross hatching? It makes sense for that G0 to cause undetected sound issues since all PCM data goes through it, but that's all it's used for (see the wiki pinouts).
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    MVS Z80 error

    The bottom of my BIOS page has the pins to check for bank errors but I would also check Z80 A11~A14 to the CHA connector. SDRD0 from NEO-D0 should pulse on every M1 bank swap which most games do constantly. I think you're almost done if this is the only thing left. edit: forgot to mention...
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    mv2f watchdog

    It has an SDIP64 package. They came in both the full size DIP64 and SDIP64 packages so make sure it's the right one if you decide to try a swap. A quick summary of what I think since I don't have much time right now: The stuck HALT pin is coming from either the 68k or B1. There's a very...
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    mv2f watchdog

    BR + BERR on 68k can be checked too. They should be high through some resistors near the 68k. Apart from that, 68k CLK should be pulsing as with the C1 CLK. With the watchdog disabled, what does 68k HALT look like? It should be low only for a short time on power on and completely high after...
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    mv2f watchdog

    Some traces to check if BIOS /OE is completely dead: NEO-C1: -Everything under the 68k section on the wiki including the A22/23 pins from NEO-E0 https://wiki.neogeodev.org/index.php?title=NEO-C1 NEO-E0: -68k address -"VEC" (from 74259) -A22/A23 outputs (to NEO-C1)...
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    Neo Diagnostics ROMs

    AES 3-6 doesn't have any 74245. The closest thing is the 2x 74273 which are also connected to palette RAM but are used for RGB output instead. Did you check NEO-G0 pinout to 68k/from palette RAMs? On AES 3-6, 68k data for palette and memcard goes through NEO-G0...
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    Eprom Programmer?

    I can vouch for the TOP3000 too. 16bit EPROM support out of the box with no needed adapters is great. No problems with the stock PSU either. Up until now I used the 32bit software in WinXP Mode but I just tried the new 64bit software and it seems to work fine natively.
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    Neo Diagnostics ROMs

    A future version could just add a few of those in the sub menu but I'd need to update the SM1 for the first time. Only the SP1 ROM has changed up until now. Have you had to replace a YM2610 that had audio/muting issues when running for a while after power on?
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    Using 2x 27C322 Eproms to replace a bad 64mbit prom? (C rom)

    We have a guide on the wiki with glitch images for reference: https://wiki.neogeodev.org/index.php?title=Graphic_glitches If the bars were on top of everything with all odd/even pixels affected then it sounds like S ROM data (bottom of that page). If that's the issue, then the S1 ROM on the...
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    AES 3-5 Video Issue

    The pattern in the pics looks like one particular trace from the LSPC2 to the cart slot is bad. We have a guide on the wiki with these sorts of glitches with what to check on the board and yours looks like the one here in the first row of that table. It looks like 2 separate graphic problems but...
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    Recent distorted sound in a AES cart

    Can you tell if all of the PCM sound or is distorted is some of it playing back properly? If it's FM synth or the square wave (which isn't used as much, mainly the chiptuney credit insert sounds and Nazca games) then it won't be affected by the VROM parts on the cart so all of that should still...
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    Neo Diagnostics ROMs

    A bad EPROM burn is the simplest cause. If it verifies OK or it's the only system it happens on, then it's possibly a lower address line to the BIOS but it's not as likely. It'll probably be A12 or A11 if any for the 68k side. If it's an upper address line (A13~A15), it should catch that as a...
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    Question about MVS schematics

    I don't think there's any 2 slot schematics out there but there is a wiki page with 2F specific pinouts: http://wiki.neogeodev.org/index.php?title=MV-2F The 1F schematics are still good for all the "core chips" and their connections. Anything that leads to the cart slot on the 1F isn't valid...
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