Got some neo geo mvs 4 slot x2 single x2

[Ratsalad]

Drove a few hours today to pick up some untested neo geo mvs mother boards ..

All 4 go to the cross hatch and hang

Mv1fz x2
And 2 4 slots



I’m going to try checking all traces for continuity around the dreaded batteries
But any other advice really appreciated thanx

 

[Neo Alec]

The cross hatch screen is a good sign that things are okay for the most part. It indicates the game program rom isn't being read.

Also make sure none of these have the pause switch (switch 8) on.

 

[mainman]

Ok, I am guessing you cleaned the test cart and the slots. You will need to isolate the faults to top or bottom board. Start by disassembling all 4 mobos and swapping top and bottom boards.

If this doesn't get you a mobo that will boot the cart troubleshooting will take longer as you have no baseline of what works and what doesn't

 

[Ratsalad]

The cross hatch screen is a good sign that things are okay for the most part. It indicates the game program rom isn't being read.

Also make sure none of these have the pause switch (switch 8) on.

Thank you

 

[Ratsalad]

Ok, I am guessing you cleaned the test cart and the slots. You will need to isolate the faults to top or bottom board. Start by disassembling all 4 mobos and swapping top and bottom boards.

If this doesn't get you a mobo that will boot the cart troubleshooting will take longer as you have no baseline of what works and what doesn't

Thanks ..
Yeh I have been closing that and swapping the bios just in case bios was bad .

I have read lots discribe cross hatch of death ? Is this just hocum?

 

[Neo Alec]

Thanks ..
Yeh I have been closing that and swapping the bios just in case bios was bad .

I have read lots discribe cross hatch of death ? Is this just hocum?

Well, the cross hatch is normal behavior for a working board with no cartridge inserted, so the cross hatch alone is not bad. The system is booting normally.

The issue is there could be any number of problems with the cart slots and/or connections to them. On your 4-slot boards this could be more difficult, but your 1-slot boards should be easier to troubleshoot.

Get a cleaner like Deoxit for the cart and slots if you haven't already. After that you'll need to get out a multimeter and start testing connections.

 

[Ratsalad]

Well, the cross hatch is normal behavior for a working board with no cartridge inserted, so the cross hatch alone is not bad. The system is booting normally.

The issue is there could be any number of problems with the cart slots and/or connections to them. On your 4-slot boards this could be more difficult, but your 1-slot boards should be easier to troubleshoot.

Get a cleaner like Deoxit for the cart and slots if you haven't already. After that you'll need to get out a multimeter and start testing connections.

I have deoxit gold

 

[Ratsalad]

Cool .. some good news to report ..
4 singles all now fully working cleaned cart slots and the cart slot pcb contacts
Now reading carts and sound all good .

I am only Looking at 1 of the 4 slots at the moment .
What I have done is check the traces around around battery and


I have 2 bad traces to that bottom chip
And 1 bad trace to the tip chip ..
So fingers crossed when the kynar wire in place this one will be working too

 

[Neo Alec]

I knew it! Nice work. Keep'em coming!

 

[Ratsalad]

I knew it! Nice work. Keep'em coming!

Thanks for your advice ..
I’m working through lots of stuff so even though it seems obvious to clean the slots etc.. I just needed someone to to say to me …. Clean the slots ! so thanks

 

[Ratsalad]

Bad traces from batterie leak repaired
Diag bios passes all tests ..

Stuck at cross hatch ..
My psu only goes to 4.9v

Does this Bohimoth need 5+ ?

 

[lithy]

Hopefully someone has better info for you because I don't know but just as a piece of info, my 4 slot cab runs at about 5.1v.

 

[Ratsalad]

I’m now getting to the test screens calander but not reading the carts

 

[Ratsalad]

My other 4 slot acquired together with this one .. was doing excactly the same
But all of a sudden this one just works..

I didn’t remove battery on this one but I have now.. it leaked but only out of one leg and the back leg as well so it was away from traces .. just luck I guess .
Way it goes

 

[mainman]

My other 4 slot acquired together with this one .. was doing excactly the same View attachment 81973
But all of a sudden this one just works..

I didn’t remove battery on this one but I have now.. it leaked but only out of one leg and the back leg as well so it was away from traces .. just luck I guess .
Way it goes

Great, you can now use the working one to fix/troubleshoot the bad one

 

[Ratsalad]

Bottom pcb no link cable connector on the pcb?

 

[Ratsalad]

Great, you can now use the working one to fix/troubleshoot the bad one

Nah diffrent size 4 slot

 

[Ratsalad]

So I have here 2 mv-4v both same

1 has power connector & one dose not ?

What’s the story ?

 

[mainman]

I just finished repairing my buddy 4 slot, haven't even reassembled it yet and he's not in a hurry to get it back. If you don't want to fix those 2 4 slots yourself and are willing to wait 3 months I can get them going. This is conditional upon how physical damaged the mobos are.

 

[lithy]

I believe it is ok to leave off. It was a jumper from the top to bottom board on some early 4 slots. I recently found that out as I got an early 4 slot.

JP1 and SW1 on 4-slot, what's their purpose?

Just wondering if anyone knows what these are for. I have searched extensively online but have not even found a reference to the existence of them. Pictures are clickable for a better view. Comments are appreciated. :) Top board with JP1 location JP1 on top board Bottom board with JP1 and...

www.neo-geo.com

 

[Ratsalad]

Am I safe to make this power jumper connect say with a jumper wire …?
Reason being I have a hunch my top board isn’t getting voltage and this is why it isn’t booting.


All tests pass with diag bios
And three corroded traces repaired ..

 

[channelmaniac]

Not needed... Clean the slots and take a close look at the connector next to the battery. If it has green gunk on the pins you'll need to replace it and the mating connector on the top PCB. If you have to replace the one on the top PCB check the traces under it after you remove it as the battery damage can crawl up through the connectors and damage traces on the top board.

Also look at the Backup RAM pins 20, 22, and 27 for missing signals. If any are missing check the battery backup area for more trace damage around the HC32 chip. That's a common cause for crashing. You can also try to flip all the DIPs on to put it into a forever loop of Work RAM Test to see if it crashes out with a memory error of some sort.

 

[Ratsalad]

Thank you
Channel manic I was reading your repair thread last night help full also

That gives me
Some more investigating thanks
I have tried the w ram setting and I get
Main ram test message just hangs like this .?

Yes I have green down in the connector 32 pin type next to the battery that
Has leaked ?

 

[Ratsalad]

Pins A11,12,13 traces dead ..

So three more to repair then hopefully
Thanks for the info on c10 green ..

Don’t worry about the wet look I’m neutralising the corrosion ..

Hope with this 3 extra dead lines to repair ..

Repaired B5,6&7 traces already .

Some green in the c10 so let you can see on pic but it’s tiny I’m neutralising no corrosion under the plastic on the metal legs and no corrosion to underside of top board .
Just praying to the neo gods this three dead lines will recover the board

 

[Ratsalad]

Fixed them 3 no dice !

Checked the B’s on bottom row of the c10 ..
Found another 2…

My other 4 slot though ..
No bad traces and it’s doing excactly the same - Just won’t boot !

Passes all tests as well.



I have another 4 slot ( number 3)

Slot 1 works perfect ..
Slot 2 no sound
Slot 3 no sound
Slot 4 no sound ?