what i am doing wrong ?

[Raver]

hello, I am having some difficulties with the installation of a Unibios 4.0 on a neogeo MVI1B. After installing the socket and the chip by following the assembly instructions I have this image on the screen.
I first thought I had damaged the MV1B motherboard, unsoldered the socket and the card worked normally again. I tested with another socket it's the same, I tested with another Unibios (I bought 2 from the same seller) it's the same. The welds are correct. I really don't understand what's wrong. I am attaching photos so you can tell me if something is not correct. Thank you in advance.

 

[Raver]

This person seems to have the same phenomenon but did not indicate how he solved the problem

NeoBiosMasta MV1C Problem

Hi people, i installed correctly the Neobiosmasta mod on my MV1C with Unibios 4.0 ( bios ok ). But the problem is when i try to start the system dont boot, i see the screen with artifacts and errors, if i remove the mod MV1C works fine again. What is the problem? maybe the bypass with pin 10...

www.neo-geo.com

 

[Neo Alec]

Is that a BiosMasta, or did someone make their own version?

Looks a bit messy. Is your pin 2 wire touching pin 3? Check continuity. You may want to just use a solder bead between pins 1 & 2 instead of a wire, for neatness.

 

[BlackSpy]

Is that a BiosMasta, or did someone make their own version?

Looks a bit messy. Is your pin 2 wire touching pin 3? Check continuity. You may want to just use a solder bead between pins 1 & 2 instead of a wire, for neatness.

Yeah, you need to check that connectio.

 

[BIG BEAR]

make sure you are not bridging connections next to eachother.
BB

 

[Misos]

You need to work on your solder skills. You have cold solder joints. You apply solder to the pad, to the wire and then apply heat and solder them together with more solder.
Sometimes due to the age of the board the pins on the 68k get dirty and you need to find something abrasive and clean them up.
A very fine grit sand paper or a fiberglass pen.
Also, I don't known where you did get that adapter but Gadget Uk had an issue with his version because he used a DIP socket and the socket didn't make proper contact with the 68k.

 

[Raver]

hello, I could not take the time to continue to take care of this project but today I was able to redo the welds as best I could (I put photos in attachments). I tried to do them as cleanly as possible. I very lightly sanded the cpu. I bought a unibios 4.0 chip from another seller, I changed the socket and I still have the same phenomenon. I don't understand.

Is it possible to solder the unibios chip directly to the MV1B1 motherboard? do you have an assembly manual? Thank you

 

[Raver]

i found this : https://8bitplus.co.uk/projects/unibios-install-neo-geo-mvs-mv-1b/

 

[BIG BEAR]

My suggestion to you would be to remove everything in order to get it back to it's opriginal state to see if it's
still functioning that way.
Some of those 3rd party sockets are really flimsy.I purchased one that would't grip my Z80 firmly enough. Then I
got ahold of an original with a heavy duty socket and it powered up fine.
BB

 

[hatmoose]

use only lead solder. 60/40 or the more "modern" 63/37 are both fine - lead-free solder is almost universally hated
Flux, lots and lots of flux, I use flux paste on the end of a q-tip for this kind of thing. Most solder says that is has a flux core - ignore that, apply more flux.
Volutar has a very weird sense of humor but he does some good modding videos

 

[Raver]

that's it, it's settled! not in the way I would have liked but at least it works. yesterday I started to be quite annoyed by the situation. I did the continuity test with a ohmmeter everything was good. I removed the original bios chip and welded with wires each of the legs of the support and it works, it's ugly but it works. with all the tests, the welds redone, the change of unibios chips, the only thing I see is that the contact had to be made badly on the CPU. Thank you for your advice

 

[BIG BEAR]

that's it, it's settled! not in the way I would have liked but at least it works. yesterday I started to be quite annoyed by the situation. I did the continuity test with a ohmmeter everything was good. I removed the original bios chip and welded with wires each of the legs of the support and it works, it's ugly but it works. with all the tests, the welds redone, the change of unibios chips, the only thing I see is that the contact had to be made badly on the CPU. Thank you for your advice

OK. You went with the old school method and did a direct solder to chip. Did you use a socket or no?
BB

 

[Xian Xi]

Just by looking at the pics, the socket isn't fully seated. You need to snap it on, put fingers under the board and on the top of the adapter and squeeze. The gap should only be about 0.25-0.50mm.

 

[Atro]

Just by looking at the pics, the socket isn't fully seated. You need to snap it on, put fingers under the board and on the top of the adapter and squeeze. The gap should only be about 0.25-0.50mm.

Great to see you back James.

 

[ggallegos1]

Damn, I thought this was a war room ranting thread about terrible life choices and blaming accountability on addiction, terrible self esteem, and signs of autism.

Good luck with your neo, man.

 

[Heinz]

Damn, I thought this was a war room ranting thread about terrible life choices and blaming accountability on addiction, terrible self esteem, and signs of autism.

Good luck with your neo, man.

Perfect thread title for that.

I still don't like your soldering but you at least made it cleaner.