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I'll go on a limb and say this doesn't look too terrible. As you say you can retin exposed traces, and maybe bodge wire if some lines are cut. The real work is figuring out if a chip is dead on the top board. You can do tests with the bottom board only with diag bios.

I already tried a Magician Lord convert on modern boards and doesn't work, maybe with extensive rom data manipulation it coukd be done, as earlier games had ADPCM A / B stored separately. C data also needs some work as there are some glitches. Ultimately I used a puzzled donor. Repro PROG-EP and...

Capacitors labelled PC are Power Capacitors, 100nF ceramic. They are typically used near every IC to filter their switching noise. However they are not critical. Watchdog loop is CPU not getting program to execute right in one way or another basically (please all experts here correct me if I'm...

CRE401 can fail internally, on each line there's a pull up resistor, an inline resistor and a capacitor to ground. Cap failing short makes input always on. https://wiki.neogeodev.org/index.php?title=CRE401

MV1B has no F0 However, looking at pics, it looks like dips are connected to a NEO-BUF, which are notorious for failing.

TOP3000 has an unlock command that does nothing in this case. GQ-4X4 has a Temp unlock checkmark that is grayed out, and I did not find anything to activate it, and there's no unlock command in menus.

So it was sketchy as, but it actually worked in the end. Had to lift leg as the trace went under the chip, then connected to an adjustable DC supply. After some unsuccessful tries, I managed. Set to 5v initially for id check, set to 12v then erased, back to 5v to blank check, then 12v for...

This is a bit beyond my skills =O But anyway, looking at that, it seems that locking is definitive and I don't have the temp unlock option in either programers I have at hand (top3000 and gq-4x4). It is present in the gq but it's greyed. Oh well, learning I guess. so if you plan on reusing...

I just managed to program some AM29F032, but for some I can't erase them anymore. Since the programer (TOP3000) checks the protection option by default, I was wondering if the protection is permanent and cannot be reversed. There's an unlock option in the menu, it confirms but result is the same...

ah dang, yeah, Prehistoric Isle would help forget the abomination that is PI2

Coin, cursor sounds typically come from YM2610 SSG channels, which are directly output by the 2610 and mixed after the DAC. It means all the amplification is working and the fault is before. Gotta check DAC itself, lines between DAC and 2610 (3 traces), 2610 itself. I guess the opamp between the...

On the diagbios page, CRC error is mentionned as bad EPROM burn, but I've read (here ?) that it can be related to 68k address / data lines being pulled up / down / jointed. I personnaly had CRC error caused by a bad 74HC259.

On my repair notes, I have Calendar crash (stuck on green screen) causes as : -RTC chip faulty -RTC / Save RAM battery power line. With diagbios you can test if RTC pulses are in sync. IIRC Unibios just bypass Save and RTC tests I had a 1F board where RTC test was wonky, but with the logic probe...

NG Double Dragon is a fighting game. OG Double Dragon is a beat them up. Not gonna lie, an OG Double Dragon without slowdowns woul be kinda dope.

For what it's worth, I launched my 161-1 and selected MSX (NOT in picknmix mode), and after about 45mins I lost sound, then shortly after it gliched in the same way as kikaso. Same setup as before, MV1A, 200ms Uni4, system set to US / Arcade.

Well, did a double ram clear (all dips down, then hardware test clear page), set to us / arcade and lost sound in about 6:30 mins while in attract. System is MV1A, with the 200ms EPROM of earlier. And I then test Magician Lord and I lost sound in like less than 3mins.. Like, 3-4 attract loops...

for kicks I tried a unibios on a 200ms (!) EPROM I had, and it worked no problem for over an hour.

Controller inputs not working is bad news most of the time. With luck it can be a bad trace, a bad CR pack (the red things), but most of the time it's NEO-C1, which dies very often and consequently hard to source from other dead boards.

ST M27C1024-10F1

I'm lucky I have a Metal Slug right now that I have repaired, so I did 2 1-hour demo runs, 1 on an MV1A, 1 on a MV1FZ, and both never glitched or crashed in any way. Using the same unibios 4 chip for both.