Problem Neo-Geo 4-Slot Graphics / Graphical Corruption

eliotcole

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Hiya ... I'm not posting this with any expectation, or entitlement to anyone's time ... but if anyone can suggest anything obvious that I'm missing, here, then that'd be great.

I'm seeing graphical corruption upon startup (or game switching) on my 4-slot inside a Lordsvale cab.

There's a couple of videos attached, and it either looks just like those, or similar.

These issues were occurring before and after the below resolution attempts, and their severity has not changed. Plus the cab was previously running Fatal Fury 2, Aero Fighters 2, Shock Troopers 2nd Squad and Metal Slug X, just fine for the previous owner.

Things that I have tried (all cleaning done lint free with contact cleaner - no, not deoxit):
  1. Slot Cleaning - Contact cleaner on a hanky wrapped around old credit card repeatedly inserted and pulled out
  2. Cart Cleaning- I have:
    1. Thoroughly ... cleaned 3 carts inside and out (Puzz Bobb - from ukv, Garou, Crouching Tiger)
    2. Contacts Only ... and on one, which I've only tried once, just cleaned the contacts (Sidekicks 2)
  3. NEO-GEO Board Cleaning - I have also tried cleaning the main boards
  4. 5V Meddling - I have (on private advice) tried slightly altering the 5V from the arcade supply around 5.10V-5.16V (without going over 5.2V) to no avail
  5. Slot + Carts - I've tried all possible configurations of carts in slots including none - the crosshatch is corrupted too
  6. Insertion Depth Variance - I've tried the carts at various lengths of insertion in various slots
  7. Harness Connected + Seated Precisely - I have ensured the pins are perfectly aligned
None have had any effect :(

I have also tried a couple of other devices on the JAMMA connector, and they worked just fine ... but I was told that I shouldn't have done that purely because it may have damaged those devices ... I'm hoping not, though. Those devices were a World Rally 2 PCB, and a NEO-GEO 1-slot (the latter of which showed each game working) ... the 4-slot issues were occurring before and after connecting these to the JAMMA connector.

What else can I try before involving someone with a little more ... intricate knowhow?
 

Attachments

  • vid 2.zip
    8.4 MB · Views: 16
  • vid 1.zip
    6.6 MB · Views: 5
Last edited:
TheDaddy

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Main thing on these are voltages , but it seems hou have done that already. My only question is , has this 4 slot worked in this cab before and has just started playing up ?? If all 4 slots do the same then its most likely the bottom board. I assume same corruption no matted what slot its in ??

Dave.
 
eliotcole

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Yes to everything here:
TheDaddy said:
Main thing on these are voltages , but it seems hou have done that already. My only question is , has this 4 slot worked in this cab before and has just started playing up ?? If all 4 slots do the same then its most likely the bottom board. I assume same corruption no matted what slot its in ??

Dave.
Click to expand...


Yes to everything here (at great pains to do so,too!):
Flyback2021 said:
Basic things I know
-Are the top and bottom board correctly seated and fully engaged ?
- Harness correctly aligned with pins on Neo geo board ?
Click to expand...


That's probably my fault, I'd believed that saying connector was specific enough ... apologies, there.
pooman2084 said:
Cool. I was confused when you said you’d plugged jamma boards in.
Click to expand...


I'll edit the OP some more.
 
neoretro

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This was my old Lordsvale that I sold. I ran it before it was loaded into the buyers car and it was working fine. Had it running fatal fury 2 for a little while with no issues.

Whatever has happened occurred during the drive back which would lend weight to something coming loose or a voltage going off.

The only other thing I suggested is that there might be a bootleg.

The 4 slot is running a unibios so you can garner some help from that.

When you checked the 4 slot voltage on 5v was the PCB plugged in?
 
jerryspaghetti

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eliotcole said:
Didn't want to involve you, @neoretro, mate, as I didn't want this to look like a jab at you (which it isn't!!), y'know?
Click to expand...
Fair play, was obviously in good shape on collection. It does help isolate certain problems knowing that is all. Was it brought in from the cold and fired straight up without acclimatising? We've all done it!

Chances are that one or more of the WRAM might be on the blink. Pretty common and a cheap easy fix if you have the tools.

I highly recommend getting that Diagnostic chip for starters.

Assume the battery has been removed previously and no damage around there? Another classic problem with these.
 
neoretro

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jerryspaghetti said:
Fair play, was obviously in good shape on collection. It does help isolate certain problems knowing that is all. Was it brought in from the cold and fired straight up without acclimatising? We've all done it!

Chances are that one or more of the WRAM might be on the blink. Pretty common and a cheap easy fix if you have the tools.

I highly recommend getting that Diagnostic chip for starters.

Assume the battery has been removed previously and no damage around there? Another classic problem with these.
Click to expand...

Battery is gone from what I can remember.

Yea you will need to test the voltage at the Jamma side. You’ll need to be very careful with this if you’re new to it as theres a risk you’ll short 12 and 5V

I had a 6 slot that didn’t run with 5.2 at the Jamma power supply.
 
eliotcole

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OK, good ... I was doing it at the +5V terminal on the black box, and grounding on the ground a couple of points below it.
...


Hey, Jerry, yeah ... no, I was given good advice on that from neoretro (hairdryers and all that stuff) ... and it was sat in a nice warm (and dry!) room for a day or two before I even had the energy to get it started up anyway 😅
jerryspaghetti said:
Fair play, was obviously in good shape on collection. It does help isolate certain problems knowing that is all. Was it brought in from the cold and fired straight up without acclimatising? We've all done it!
Click to expand...

I might even have a diagnostic chip ... I can't remember, I'll have a dig around.


Anyway ... it should also be noted that it has run a couple of times OK ... but now it is garbled all the time.

I've not dropped, hit, bumped, done anything bad ... it's been kids gloves all the way ... so perhaps something just got shorted? I dunno ...

I'll look into WRAM stuffs ... ... cheers!

Also, am heading to Retroman839's at some point soon, and he's got some experience in this area ... so we'll troubleshoot if we can, then.

Thanks all!
 
Last edited:
eliotcole

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OK, so ... as per the advice from others, and below ... I'd been testing the voltage on the black box ... and had not taken it above 5.19v at all.
neoretro said:
Yea you will need to test the voltage at the Jamma side. You’ll need to be very careful with this if you’re new to it as theres a risk you’ll short 12 and 5V
Click to expand...
---
Today I did a bit more testing on it, and it's still the same. This time, though, I chased the wires to the 4-slot connector of things ... and the voltage is much lower there.
I don't have the exact measurements (will update when I get the piece of paper I left in the kitchen) ... but I seem to remember that it only got to 5v on the 4-Slot connector when the voltage was around 5.35v or something at the arcade black box.
---
Either way, without a cartridge, at a few voltages, but never higher than 5.10v at the 4-slot connector it always displays the attached screen:
processed.jpeg
Most of the time it does that with a cartridge, too ... sometimes it boots to the game ... but it's corrupted/garbled on screen.
Is this indicative of a memory chip being fried or something?
 
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