Attempt repair on MV-1F

bigadz

n00b
Joined
Mar 14, 2015
Posts
2
Hi guys!

LONG time stalker, first time poster.

I was recently gifted an MV-1F that was deemed dead by a friend getting out of the hobby and a 161 in 1 board. The MV-1F has sat for many years unused and I'm contemplating a repair, though this may be something outside of my skill.

I booted up the MV-1F on my Raijin and it goes straight to a Z80 error.

Giving the board a look over a couple of things stand out:

- The battery has been removed but there appears to be corrosion around one of the terminal legs that remain
- It looks to have been attempted to be cleaned with something on the back side of the board as it looks like it has some kind of white residue on it or the PCB wax has deteriorated?
- There does seem to be some corrosion around the area of the battery, but I'm not sure how significant this is

I am handy with a soldering iron, however not a master of it by a long shot, but I'm thinking if it's worthwhile giving a repair a shot or just keeping it for spare parts. I've got multiple other arcade boards and 2 full cabs that I've spent time wiring and messing around with but never attempted a PCB repair, closest would be soldering arduinos or esp8266s.

I've linked to some pictures and would be really happy for someone with more experience than me to weigh in and say if I'm wasting my time or if this bored has a shot at living.

If I do go ahead I'm happy to document the process of a noob trying to repair something, including all of my screw-ups that will inevitably happen.

https://drive.google.com/drive/folders/198OGkfeWZRHxJ5V8SLeabKLyg9hAPDjH?usp=sharing

I'm happy to take additional pics if they are of any use to anyone to help me diagnosed or set me on the path of where I should look first. I don't have a logic probe or oscilloscope but I do have a soldering iron, a desoldering gun, a hot air gun, a multi-meter and at least a little courage lol

Thanks!
 

HeavyMachineGoob

My poontang misses Lenn Yang's wang
10 Year Member
Joined
Apr 3, 2011
Posts
5,816
The battery on the MV-1F (and 1FS and 1FT) usually attacks the traces for the Z80 RAM chip which sits near the battery. I recommend checking those traces first, that's what was wrong with my MV-1FS, which also had a Z80 error.

Jamma-nation-X has some repair pinouts available for the 1F series. Use the below link, pick Neo Geo, then MVS, then scroll down for the MV-1F pinouts.

http://www.jamma-nation-x.com/jammax/tutorials.html

Code:
1 - SM1(5), Z80(37)
2 - SM1(6), Z80(36)
3 - SM1(7), Z80(35)
4 - SM1(8), NEO-D0(32), Z80(34)
5 - SM1(9), NEO-D0(31), Z80(33)
6 - SM1(10), NEO-D0(30), Z80(32)
7 - SM1(11), Z80(31)
8 - SM1(12), Z80(30)
9 - SM1(13), NEO-C1(74), Z80(14)
10 - SM1(14), NEO-C1(75), Z80(15)
11 - SM1(15), NEO-C1(76), Z80(12)
12 - GND
13 - SM1(17), NEO-C1(77), Z80(8)
14 - SM1(18), NEO-C1(80), Z80(7)
15 - SM1(19), NEO-C1(81), Z80(9)
16 - SM1(20), NEO-C1(82), Z80(10)
17 - SM1(21), NEO-C1(83), Z80(13)
18 - NEO-D0(12)
19 - SM1(23), Z80(40)
20 - SM1(2), NEO-D0(39)
21 - NEO-D0(40)
22 - SM1(26), Z80(39)
23 - SM1(27), Z80(38)
24 - VCC

All you need is a multimeter and some time to go through those pinouts. What you'd be looking for is either no connection or really high resistance on a given trace between the 6116 RAM chip and wherever it's supposed to go to. High resistance can be a symptom of corrosion damage. Low or no resistance should mean the trace is good.
 
Last edited:

bigadz

n00b
Joined
Mar 14, 2015
Posts
2
Thanks so much for this HMG!

I've been looking at the schematics for the MV-1F too so will see how I go with continuity/resistance checks.
 

BIG BEAR

SHOCKbox Developer,
20 Year Member
Joined
Dec 14, 2001
Posts
8,230
I picked up an mv1f where the battery went bezerk spraying,not leaking but sparing it's acid all over the sound section!
Components need to be replaced and traces/tracks repaired.
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