MV 1FZ my first steps

Dore

n00b
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Sep 9, 2018
Posts
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Hey everyone. I'm very-very new to the SNK family. I Just received two MV1FZ boards in unknown condition.
I have no MVS carts atm but i do have a Jamma cab for initial testing.

My questions are:
Is there any step i should take as a precaution before plugging the boards into the cab? dip-switches, old batteries etc.

What am i supposed to see if i plug a board in, without a cart? A logo, a warning, an error, nothing?
 

ggallegos1

Cholecystectomy Required.,
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If anything, flip all the dips to "on" to clear the backup Rams.

Inspecting the PCBs, look for signs of acid damage, cold traces, or corroded components. Especially newr the battery, if it's an OG battery see if there is any acid leaks. Clean it up pretty good if you can.

When you turn it on with no game, you will get the cross hairs. Holding "BCD" on startup to access soft dips to test the controls, etc.
 

ggallegos1

Cholecystectomy Required.,
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See if you can download the PDF of the user manual for a MV1-FZS, it will tell you everything you need to know
 

RyuX

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You want to get yourself a SNK Diagnostic Bios (burn it on a 27C1024 or similar chip).
I use the AT27C1024 and burn it with my TL866A Programmer.
http://smkdan.eludevisibility.org/neo/diag/

This will show you Address and other Errors related to most common faults.

If you can't even get a picture and only have a garbled screen then I would start by checking all the traces for visual damage as well as touch all the ICs when powered on and feel if any of them get hot.

Then I would systematically replace the ICs with a reflow station (U1, U2, etc.)
Always make notes what you changed and what state the system was after/before the change.

Most commonly you will have faulty Backup or Video Ram (Fast or Low Video RAM) as well as broken HC32 or 4990 in the Backup Area.

In some rare cases also the SNK Chips can be damaged (NEO-B1, LSPC2-A2, etc.) but those are the things I would replace only if nothing else will help.

Most of the time you have broken traces or some broken ICs.

As a short guide you can use my PDF that has a little compilation of the RAM pinouts in relation to other parts (it by no means is complete - but a start at least as the schematics are sometimes hard to read).
 

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Neo Alec

Ned's Ninja Academy Dropout
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Hopefully the boards work and it doesn't come to any of that.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
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Hopefully the boards work and it doesn't come to any of that.

Yes indeed - Fingers crossed it all works out of the box :)

Out of my experience - whenever I bought a unknown condition it was broken. 6 out of 6 times
So depends where you got them from...
 

Dore

n00b
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Sep 9, 2018
Posts
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Wow thank you so much for all the info.
I don't have any 27c1024 and i'll have to borrow an Eprom burner, but i'll see what i can source. I suppose i'm gonna need them for the Unibios anyway. In case i have a working board that is.
I need to clean the boards first as one of them seems to have something that resembles white mold residue(?). At least the batteries seem to be in decent condition.
One of them has the serial scratched/removed. Any ideas why? Shady purposes, gray imports or what?

Pic of general condition:

IMG_20181019_125706.jpg
 

RyuX

Crossed Swords Squire
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Sep 19, 2018
Posts
179
Hey there

Get some IPA Alcohol ready and a toothbrush and clean the whole board (front and back).
Take your time until the board looks like new.

The good news is - you got all stock parts on that board so nobody tried to repair this board before probably.
Also looking at the Fast VRAM it seems you have a newer Revision.
Is this a LSPC2-A3 on the top left ?
 

Dore

n00b
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Sep 9, 2018
Posts
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Also looking at the Fast VRAM it seems you have a newer Revision.
Is this a LSPC2-A3 on the top left ?

Didn't know that Revisions of MVS boards had their own revisions... Yes both of them have a LSPC2-A3.
 

Dore

n00b
Joined
Sep 9, 2018
Posts
5
.

IMG_20181214_210522.jpg

IMG_20181214_211202.jpg
Hey

I plugged both of the boards today in a cab. Nevermind the overscan, it's set for a Pandora.

One of them has a weird skew on top and both of them have a vertical blue line on the same spot on the right. Where do i begin?
 
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