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Reverse engineering 161 in 1 cartridge to change Rom games

davidmorom said:
Seems like the CHA board CPLD is not addressing bank 0 for the S ROM on boot, so it is displaying tiles from another game instead of the menu. Maybe some lines of the cable that connects the boards are not making good contact? Do all the games work, or only some of them?

Obvious question, did the cart work fine before modification? Maybe some outputs of the CPLD are damaged or stuck at a fixed logic level.
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I've had different issues with the cable before (like not booting any games off of C3) so I've checked that. That's a wildly good line of thought. I've tried 15 or so games from the first to the last, and everything boots. I'll try hard wiring the cable just in case, who knows, maybe it makes good connection before being put in the cart, but bending it makes the pins stop connecting correctly? I can swap PROG boards and the issue stays, so I know it's the CHA board.

Every cart worked before modification, I made a point to run them for about two hours just so I knew I was working with okay stock.
 
nem said:
also, build guide by the man himself:

https://www.arcade-projects.com/threads/the-neogeo-v3-161-in-1-multicart-upgrade-build-guide.27994/

Good luck! Let us know how you get along!
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I need to finish this as soon as I get some free time. But by all means, feel free to ask questions. I am more than happy to answer what I know.

That dumper board, and the fantastic one by @huluhala definitely made it easier for doing dozens. Especially @huluhala 's, as it let me figure out an issue was with the chip or the daughterboard where the original dumper board and mine don't. Mine is good because you don't have to remove the cheap Chinese programmers from their sockets constantly, which makes them last a lot longer. Do be sure to put larger sockets on the sides next to the daughterboard if you use mine though, it will keep the board from flexing and the solder joints on the smaller sockets from breaking.
 
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@davidmorom Looked into one of those two tonight and fixed it with your line of thought.

Turns out that C rom A20 was tied to Vpp. A20 also happens to be GSelect[4]. But it wasn't bridged at the S rom. Traced it to the CPLD, and then back to M rom's A21 where there was the smallest hair's width of solder bridging it to Vpp. Would have taken me a LOT longer to find if not for your assessment since it wasn't even a graphics related rom where things went wrong!

Will update with what's gone on with the other one as well when I get around to that one, but was very pleased and wanted to say thank you after fixing this one!
 
rewrite said:
@davidmorom Looked into one of those two tonight and fixed it with your line of thought.

Turns out that C rom A20 was tied to Vpp. A20 also happens to be GSelect[4]. But it wasn't bridged at the S rom. Traced it to the CPLD, and then back to M rom's A21 where there was the smallest hair's width of solder bridging it to Vpp. Would have taken me a LOT longer to find if not for your assessment since it wasn't even a graphics related rom where things went wrong!

Will update with what's gone on with the other one as well when I get around to that one, but was very pleased and wanted to say thank you after fixing this one!
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Good to know! This reminds me, more than 20 years ago, a friend of mine gave me a "broken" SDRAM module that made the computer unable to POST. After a lot of testing in different computers and combinations, I looked at the module trough magnifying lens, and I saw an extremely thin and small piece of wire inserted between two pins of one of the RAM chips, shorting them. Removed it and everything worked flawlessly.

Electronics are wonderful! :huh:
 
I ordered 3 new F0095H0 on Aliexpress, I will receive it tomorrow. After sending, the seller closed the ad. As I understand it, people have already received chips from Ali here - are they really serviceable? . I haven't found where I can order the adapter boards yet, so I won't be able to check in the near future.
 
@bytestorm, @MaRC, A few days ago I received the dumper and daughter boards from JLPCB, and yesterday I had some free time to start putting things together. Good news! The F0095H0 from Aliexpress worked flawlessly, I was able to program and dump it back without any single error, and both files matched perfectly, so no damaged sectors on the chip. I still have to test it on the real cart, but there is no reason for it to not work.

Currently, I have the four F0095H0 installed onto new daughterboards and flashed with V and C ROMs. If I have some free time today, I will desolder S, M and P. Everything is going smoothly so far.
 

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davidmorom said:
@bytestorm, @MaRC, A few days ago I received the dumper and daughter boards from JLPCB, and yesterday I had some free time to start putting things together. Good news! The F0095H0 from Aliexpress worked flawlessly, I was able to program and dump it back without any single error, and both files matched perfectly, so no damaged sectors on the chip. I still have to test it on the real cart, but there is no reason for it to not work.

Currently, I have the four F0095H0 installed onto new daughterboards and flashed with V and C ROMs. If I have some free time today, I will desolder S, M and P. Everything is going smoothly so far.
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Got mine today! Looks brand new, no corrosion. Aint got any adapter pcbs yet but looks good :)
 
@rewrite can you please add me to your MVS waitlist when more come available? I figured this will be the most cost effective approach.


Also:
Has anyone had success with MVS adapter an a 9V AES with the 161 carts? Any issues?
 
Reminiz said:
Yup I’m aware just wondering if anyone local to me has taken the plunge seeing all the info and guides are out there.
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I tried, and could not get the C ROMs to work correctly after removal - this is a seriously difficult build and now that the 161 carts have tripled in price, not something I’m willing to try again
 
Reminiz said:
Has anyone had success with MVS adapter an a 9V AES with the 161 carts? Any issues?
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It's a hit and miss. It works on in most cases, but I've seen it fails in others. Furrtek does not support any multicart with his adapter. Other thing to keep in mind is that the FPGA code is different; a system reset using an MVS cart does not take you back to main menu due to a security check trigger in MVS code.
 
Reminiz said:
@rewrite can you please add me to your MVS waitlist when more come available? I figured this will be the most cost effective approach.
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Unlikely at this stage that I'll be able to provide a cart. If you have a cart and can send it to me, I can absolutely get the work done, I just can't provide the initial cart.

xodaraP said:
I tried, and could not get the C ROMs to work correctly after removal - this is a seriously difficult build and now that the 161 carts have tripled in price, not something I’m willing to try again
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Did your V rom work?
 
Because of the sanctions, most services refuse to send to my country. I found one in China that still ships, but they have a problem with dual daughter boards - they ask:
1. The distance between plated through holes is too small, can we reduce the diameter of the holes to 0.35mm? (Diameter is after plating)
As I understand it, it's okay, let them reduce it?
 
MaRC said:
Because of the sanctions, most services refuse to send to my country. I found one in China that still ships, but they have a problem with dual daughter boards - they ask:
1. The distance between plated through holes is too small, can we reduce the diameter of the holes to 0.35mm? (Diameter is after plating)
As I understand it, it's okay, let them reduce it?
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I'm assuming that you're talking about the holes for the 1.27mm pin header on the dual-daughterboard, right?

Standard spec for these holes is .7mm, the ones on the amazing dual daughterboard are a tiny bit smaller at .65mm

The pin itself is .4mm square, which works out to .56mm on the diagonal

I'm sorry to be the bearer of bad news - I just dont see any way that a .56mm pin is going to fit into a .35mm hole.
Screen Shot 2024-11-07 at 10.35.25 PM.png
 
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