SNK Neo Geo MVS MV2 (2 Slot) Repair (Graphics Problems & Corrosion)

[@GadgetUK164]

A couple of corrections - 1) When I was pointing to some of the quad flat packs saying they were 128 pin - they aren't they are 64 pin! The ZMC2 is 80 pin. 2) The BIOS wasn't sat all the way into the socket properly there at that point when I went around the chips - just needed pressing in further on the left side.

[@Fothlyr]

I have the same board with similar issues. Wanna fix it for me? 😁

[@georgelea4297]

Just got home and I've got the notification so I'm chilling out with a bite to eat and a drink can't think of a better way to spend an hour 👍

[@Four_X]

Hats off Chris that's how many Neo Geo you've saved now. I'm thinking of getting a two slot to consolize. That metal top shield would look great painted black with the blue SNK and white Neo Geo logo on it.

[@Deutschland01]

Very nice video Chris, this is the reason why i love your videos. Some people dislike long videos, but sometimes it is necessary to do that. You take your time to explain everything with calm voice, and that is good. Every person who gives a thumb down for any reason is ignorant and has probably not seen the whole video. Videos about Technology need sometimes to be longer so everyone can learn about it. People should be really thankful that you share your experience with the world! Keep up the great work, you do everything right Chris!

[@Error42_]

Legend has it that if you open up one of those barrel batteries, inside there is a tiny rolled up message from Satan himself. It reads "Ha ha f*** y**!"

[@CRG]

Every time |I watch you working on these boards I get the temptation to buy a broken one and try to fix it. If only I didn't also need to buy a jamma connection, controller, power supply, diagnostic rom and a game cart. Plus I'd likely just break it more lol. Fantastic video.

[@MindFlareRetro]

I'm playing catch-up again with you latest videos. I couldn't believe how much filth had accumulated under some of the ICs you removed. Great clean-up and repair.

[@james276]

You are the NeoGeo master! I bet you could start your own Arcade! I'd definately come.

[@racer4200]

Nice work! I need to break out my broken 2 slot and take another look at fixing it.

[@josephnealeUKscratchcards]

Just got your Notification just now and always enjoy your videos as always

[@tails64dsntchannel8]

There We Go, more Neo Geo! Seriously Man Keep it Up! You Rock!

[@Neffers_UK]

A comparatively "easy" fix, bet it still took hours to fix, film and edit, great job Gadge!

[@AdamSommer70]

Another very cool video, thanks for posting

[@DJlegionuk]

Great Video, I was looking for a game PCB repair project for this year after I fixed my Crazy Kong PCB last year and I found a SEGA choplifter game untested for a very good price. I am thinking of doing live streams to save editing, but I don't think testing logic chips for hours would make for interesting content.

[@DigitalConfusion]

The sliced connections are usually to the coin mechanism. Don't know if that is the case here but I have seen that alot.

[@wegi9621]

Gadget rules ! :)

[@MRMIdAS2k]

About 42:20 it's not obvious, but it's kinda noticeable with regards to the "darker area" you can see, especially on the corner of the 19/20 markings on the board. Either way, a great cleanup vid so far, always fascinating to see how stuff works, despite my lack of repair ability.

[@xephorce]

you inspire me. i am so gonna try and make a 3d printer from my old 60 inch rear projection TV.

[@AdamSommer70]

How do you go about doing that?

[@xephorce]

@@AdamSommer70 its based on the dlp style projectors people have used to make 3d printers. i would like to use that old TV seeing as its just collecting dust in the back room

[@JohnGotts]

Thanks for another classic investigation. Edit: A plastic razor blade might help with the black spongy material.

[@owencrawford8416]

Dude you're a genius

[@jasondark1478]

Another triumph! 👍

[@RetroRecollections]

You're a Neo Geo repairing wizard! :)

[@vivalafletchweekends2747]

Nice work on that really small wire trace repair coming of the chip you replaced. I have a 2 slot thats just started having some graphic errors. I removed the battery years ago and its very clean board. Im not super clued up on working out the problem but willing to try. I thinking it could be c rom data problem but where to look first?

[@GadgetUK164]

Thanks! Do the things I showed in this video to start with - probe the connections as I talked about on the ZMC2, that may provide a clue. I also suggested in the video which ICs I would suspect if the ZMC2 was OK.

[@Charlie-Cat.]

Always a pleasure to see Chris in action doing what he does best. Nice work bro. Glad you do this for the community to gain knowledge from your work. 8^) I posted this up on the Neo-Geo thread on Atariage.com for you. It's on post #17,864 for you to view. Thank you as always kind sir. 8^) Anthony..

[@pixeldoc8961]

This is a very much appreciated video. I have a similar issue with some graphics specifically on my 2 slot. The games load perfectly sound and all, but I am literally missing the bulk of sprites and background graphics. Most of the text on the screen loads. Just seems like animated graphics are not appearing. It has been suggested that I swap the ZMC2 chip and it may work. Any thoughts? Cheers!

[@GadgetUK164]

Yes, I would try the ZMC2 first =D

[@pixeldoc8961]

GadgetUK164 - Retro Gaming Repairs & Mods Thanks for the reply!

[@4Tune2000]

I have a question about neutralising after cleanup. I have a board just like this, with a leaking battery - a NiCd battery. I read elsewhere that NiCd leakage is acidic, and therefor needs to be neutralised with something with a high PH value (basic) like baking soda. And alkaline batteries leakage is basic, and thus requires something acidic like vinegar to neutralise it. I dont know if this is correct, but it seemed that your battery was also a NiCd, and you mention neutralising it with white vinegar. Do you have any comments about this?

[@GadgetUK164]

NiCd is alkaline! Just use White Vinegar (distilled) to clean up. You should be cleaning up again afterwards with IPA anyway and washing away any contaminants etc, or really makes very little difference to be fair. See here:- www.sciencedirect.com/topics/engineering/alkaline-electrolyte

[@elspuddy]

Quick question , I’m thinking of picking up a single slot neo geo from the bay (not to fix just play games on), would it matter if I import one from China or out side of the uk ?

[@GadgetUK164]

It shouldn't make a difference! Most of the ones from China tend to be MV1C or MV1B boards.

[@masudhussain4587]

dear how you get this diagnose option in motherboard when repairing. is it on dip switch? which switch please sir help me.

[@GadgetUK164]

The diagnostics is not built into the standard BIOS. You need to get the "SMK Dan Diagnostic BIOS" programmed to a 27C1024 EPROM.

[@NeoGeoLand]

Chris my neogeo mv2f does not recognize the cartridges, you call goes straight to the crosshatch screen, do you have any idea what it is?

[@GadgetUK164]

You will get stuck at the cross hatch screen if the 68K CPU cannot access the P ROM(s) on the cart. That could mean that the databus to the P ROMS has a connection missing, or an address line missing. They dont go straight there on a 2 slot obviously, they get buffered - probably through Neo-G0 or Neo-257's or something. You would need to follow the CPU databus connections and try and work out how they get to the cart slots, or reverse it - start at the P bus data and address connections on the slots and see what they connect to.

[@therealcojo]

Really enjoy your videos! I've been working on my own mv4 and I've learned a lot. My 4 slot has a perforated cover, seems most covers are solid, were the mesh ones early builds? Any ideas?

[@GadgetUK164]

Honestly no idea - never seen a perforated cover =O

[@therealcojo]

Here's a photo, it's the only one I have handy, before I pulled the board out of the cabinet. Just to show you something you've never seen :) Once again thank you for your hard work, it's very appreciated! m.imgur.com/a/Tqn29wW

[@GadgetUK164]

Wow, that is rare! Very nice =D

[@therealcojo]

Thanks! Super stoked on it just waiting for some new ram chips to come in, Ive got one bad video ram chip, I'm able to bypass the error using unibios and it's playable, minus the graphical glitches from the bad ram chip. These brassy/golden "mesh top" covers seem to have come out of early "Big Red" north American cabs like mine, I've been trying to find more information. imgur.com/a/KWbEsYr

[@dominikschutz6300]

Maybe caius could provide replacements for those custom chips.

[@MarcoVirgulti]

Thanks for your videos!! I would like to ask you some information about a repair i'm working on ... i have a MV2F board with "calendar error" problem. i've checked traces from battery to 4990 ic but i've not found any leak or corrosion sign...i've changed the 4990 too but it doesn't work, same calendar error. I've tried a working mvs board with oscilloscope and compare the waveforms. i've seen that the 4990 works but its serial interface is not clocked by the neo-f0 ic. the clock rise up but then stucks at high level and not change (it should do 4 clock strobe to set the C0,C1,C2,C3 commands to 4990 and then 32 strobe to read date). It can be a faulty neo-f0 ic or something else? the board seems clean everywhere :( sorry for my bad english thanks a lot!

[@GadgetUK164]

It could be a faulty F0 perhaps, but often the cause will be a missing trace or 74 series IC related. Here's a schematic for that circuit which I grabbed from Neo Geo forum years ago (not sure who created it) - www.dropbox.com/s/m9lfhjqlgpbv3hf/2slotcalendarak9.jpg?dl=0

[@GadgetUK164]

Maybe swap out the watch crystal first? Unless you see the 32.768Khz there with a scope?

[@MarcoVirgulti]

@@GadgetUK164 thanks a lot for suggestions...i've seen something like that with multimeter trying to decode the routing on the pcb. i will see if it is the faulty logic gate (my wish) or a faulty F0 chip (my nightmare :(( ) Unfortunately, as i wrote above, it seems to be the CLK on the 4990 to be corrupted (from NEO F0 chip)...the 74 gate ic pins are related to chip select and output enable of the 4990, but the problem seems the missing input clock. I'll keep you updated!

[@MarcoVirgulti]

@@GadgetUK164 the crystal is fine :)

[@CoquillageCrustace]

Hello Gadget, thanks for sharing so many repair tutos. I've followed some steps to replace the Ni-Cd battery on my MV2F as settings was no longer backuped. The problem is still there even if the new battery is OK. I've noticed some corrosion on the 22k resistor close to battery and after having unwelded/welded it again (impedance measurement is ok), nothing as changed. The old battery has probably created other issues around but it's hard to spot visually. I've also some display issues, there are some vertical white lines/dots in graphics. It's visible on the NEO GEO logo when any games start on my system. Do you think it could relate to Neo-ZMC2 ? Maybe this subject was already coverd on another video ? Thanks for your help and advices.

[@GadgetUK164]

Yes, its possible the ZMC2 is creating those lines / dots. What sometimes happens though are the chips that "switch" between the slots on the C bus cause that type of issue. I mentioned that briefly in the video towards the back end I think. With regards to the settings, maybe the backup RAM is bad, or a damaged trace around that battery circuit. Get a copy of SMK Dan diagnostic ROM and test the BRAM.

[@CoquillageCrustace]

@@GadgetUK164 Hello Gadget, thanks for your reply. I've fixed the problem few days ago. You were right, the white artefacts were caused by 2 damaged traces around that battery circuit. The corrosion from the leaking battery broke them. Hopefully the damages were not so big. I've replaced the battery with a new Ni-Cad one but I've welded it on the other side of the circuit. I know it's not the best way to avoid again this problem but I saw too late the replacement with a Ni-Mh accumulator option. Now I have a display problem with my CRT TV Sony Trinitron KV-29CL-10B. There are some green horizontal wide bands behind some white/flashing graphics. It happens even when there's no cartridge plugged. I can't remember if I always had this problem as I used to play NeoGeo MVS on anoher CRT TV that just "exploded" few days ago, yeah bad luck... I've only found another guy telling about the same issue on forums but he was never answered. Have you already heard about something like that ? I've double checked the Jamma and Scart plugs, thinking about bad solder/wiring on quick synch, video ground, or green output. Very rare issue...

[@devmiles]

Great video's mate! I have a 2 slot looking extremely clean and nice but i find the graphics very dark-ish on my Sega Blast city. Also the cards do not work all the time, glitches etc. Do you have any idea how to fix it? Maybe some new capacitors?

[@GadgetUK164]

It could be a voltage problem - check your 5v level is good on the board whilst its powered? Alternatively, if the video is still dark, maybe there's a DAC problem. I think its done with some 74HC chips, and resistors on these?!? If carts are not working all the time, clean the PCB edges on the carts with IPA. Also consider cleaning the cart slots with deoxit or contact cleaner. If carts still fail to work you may have a fault on the top board.

[@devmiles]

@@GadgetUK164 I had my board recapped but didn't fix the issue. The problem with my Blast city was that i still had the VGA cable inserted causing the darker image on Jamma. Solved now!! Looking for a MVS 2 slot headphone jack replacement since i accidently broke mine. Any idea where you can buy this part? Heard they are rare.

[@blackcountryme]

Falling asleep, have to continue tomorrow

[@andylynn7884]

Genius.

[@slaytallica136]

Use aluminum foil on the RF shielding with some kind of liquid.

[@Grandtimelord]

What tools are you using if you don't mind me asking?

[@GadgetUK164]

Back then I was using a cheap Antec 15W iron (around £15), and the Atten 858D (Hot air station) -around £60 ish. In addition I had the Annesty desolder station too. Now I use the Hakko 888D soldering iron instead of the old Antex.

[@Fille-lj1qv]

Nice fix gadget,how many mvses you own ?

[@GadgetUK164]

Something like 13 MVS and 1 AES I think.

[@HuntersMoon78]

1 hour quick look - damn dude what do you call a long look.

[@Heru3005]

That was a fun fix to see. You really are the NeoGeo Master! RIP Logic probe. Would some Goo Gone not take care of that black stuff on the back of the board? Not sure it's available in the UK googone.com/

[@Inkoffundivel]

58:43 name of game please

[@GadgetUK164]

The game is called "Kraut Buster" from NGDEVTEAM.

[@Inkoffundivel]

@@GadgetUK164tks :)

[@valyafyodorov2934]

try acetone or wd40 on the glue remnants

[@itamarazulai6767]

Hello, Thanks a lot for your videos they're Great and informative. Is there a way i can contact u?

[@GadgetUK164]

Yes, here lol =D I cannot do customer mods and repairs sorry!

[@itamarazulai6767]

@@GadgetUK164 That's ok, i wanted to offer u a none working mv2f board to try to fix and keep for yourself.

[@GadgetUK164]

Thanks for the offer! I just don't have the time, space or health at the moment!

[@itamarazulai6767]

@@GadgetUK164 I understand, Wish u the best and feel well.

[@diamondp.9688]

Why don't you just sink it in the water with some detergent and wash it with brush?

[@GadgetUK164]

Mainly because water can cause rust very quickly. Even if you dry it off super quick some of the exposed metal connections are affected by water. You can also end up with other contaminants under chips and in sockets etc.